Combined 2 example scripts with a bit of scripting to publish sensor data from 2 DHT11 sensors to a remote web-server using a GET request webClient_dht -- doesn't work with error code in comments below webClient -- works to post to web-server using a GET request DHTtester1 -- works to read sensor data and concatenate floats to a string and retur…

DHTtester1.ino

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain

#include "DHT.h"

#define DHTPIN 2     // what pin we're connected to
#define DHTPIN2 3     // what pin we're connected to

// Uncomment whatever type you're using!
#define DHTTYPE DHT11   // DHT 11
#define DHTTYPE2 DHT11   // DHT 11
//#define DHTTYPE DHT22   // DHT 22  (AM2302)
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

DHT dht(DHTPIN, DHTTYPE);
DHT dht2(DHTPIN2, DHTTYPE2);

char buff_h1[6];
char buff_t1[6];
char buff_h2[6];
char buff_t2[6];

String h1_string;
String t1_string;
String h2_string;
String t2_string;
String dht_string;

void setup() {
  Serial.begin(9600);
  Serial.println("DHTxx test!");

  dht.begin();
  dht2.begin();
}

void loop() {
  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h1 = dht.readHumidity();
  float t1 = dht.readTemperature();

  float h2 = dht2.readHumidity();
  float t2 = dht2.readTemperature();

  dtostrf(h1,5, 2, buff_h1);
  h1_string = String(buff_h1);
  dtostrf(t1,5, 2, buff_t1);
  t1_string = String(buff_t1);

  // check if returns are valid, if they are NaN (not a number)
  // then something went wrong!
  if (isnan(t1) || isnan(h1)) {
    Serial.println("Failed to read from DHT");
  } else {
    dht_string = "h1=" + h1_string + "&t1=" + t1_string;
    Serial.println(dht_string);
//    Serial.print("Humidity: ");
//    Serial.print(h);
//    Serial.print(" %\t");
//    Serial.print("Temperature: ");
//    Serial.print(t);
//    Serial.println(" *C");
  }
}

webClient.ino

// Demo using DHCP and DNS to perform a web client request.
// 2011-06-08 <jc@wippler.nl> http://opensource.org/licenses/mit-license.php

#include <EtherCard.h>

// ethernet interface mac address, must be unique on the LAN
static byte mymac[] = { 0x74,0x69,0x69,0x2D,0x30,0x31 };

byte Ethernet::buffer[700];
static uint32_t timer;

//char website[] PROGMEM = "www.google.com";
char website[] PROGMEM = "192.168.0.2";

// called when the client request is complete
static void my_callback (byte status, word off, word len) {
  Serial.println(">>>");
  Ethernet::buffer[off+300] = 0;
  Serial.print((const char*) Ethernet::buffer + off);
  Serial.println("...");
}

void setup () {
  Serial.begin(9600);
  Serial.println("\n[webClient]");

  if (ether.begin(sizeof Ethernet::buffer, mymac, 10) == 0) 
    Serial.println( "Failed to access Ethernet controller");
  if (!ether.dhcpSetup())
    Serial.println("DHCP failed");

  ether.printIp("IP:  ", ether.myip);
  ether.printIp("GW:  ", ether.gwip);  
  ether.printIp("DNS: ", ether.dnsip);  

  if (!ether.dnsLookup(website))
    Serial.println("DNS failed");
    
  ether.printIp("SRV: ", ether.hisip);
}

void loop () {
  ether.packetLoop(ether.packetReceive());
  
  if (millis() > timer) {
    timer = millis() + 5000;
    Serial.println();
    Serial.print("<<< REQ ");
    ether.browseUrl(PSTR("/arduino/logger1.php?pwd=secret"), "", website, my_callback);
  }
}

webClient_dht.ino

// webClient_dht.ino: In function ‘void loop()’:
// webClient_dht:112: error: no matching function for call to ‘EtherCard::browseUrl(char*, String&, char [12], void (&)(byte, word, word))’
// /home/USER/sketchbook/libraries/EtherCard/EtherCard.h:152: note: candidates are: static void EtherCard::browseUrl(prog_char*, const char*, prog_char*, void (*)(uint8_t, uint16_t, uint16_t))


// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain

#include "DHT.h"

#define DHTPIN 2     // what pin we're connected to
#define DHTPIN2 3     // what pin we're connected to

// Uncomment whatever type you're using!
#define DHTTYPE DHT11   // DHT 11
#define DHTTYPE2 DHT11   // DHT 11
//#define DHTTYPE DHT22   // DHT 22  (AM2302)
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

DHT dht(DHTPIN, DHTTYPE);
DHT dht2(DHTPIN2, DHTTYPE2);

char buff_h1[6];
char buff_t1[6];
char buff_h2[6];
char buff_t2[6];

String h1_string;
String t1_string;
String h2_string;
String t2_string;
String dht_string;



// Demo using DHCP and DNS to perform a web client request.
// 2011-06-08 <jc@wippler.nl> http://opensource.org/licenses/mit-license.php

#include <EtherCard.h>

// ethernet interface mac address, must be unique on the LAN
static byte mymac[] = { 0x74,0x69,0x69,0x2D,0x30,0x31 };

byte Ethernet::buffer[700];
static uint32_t timer;

//char website[] PROGMEM = "www.google.com";
char website[] PROGMEM = "192.168.0.2";

// called when the client request is complete
static void my_callback (byte status, word off, word len) {
  Serial.println(">>>");
  Ethernet::buffer[off+300] = 0;
  Serial.print((const char*) Ethernet::buffer + off);
  Serial.println("...");
}

void setup () {
  Serial.begin(9600);
  Serial.println("\n[webClient w/ DHT sensors]");

  dht.begin();
  dht2.begin();

  if (ether.begin(sizeof Ethernet::buffer, mymac, 10) == 0) // 3rd argument 10 added to match shield pi
    Serial.println( "Failed to access Ethernet controller");
  if (!ether.dhcpSetup())
    Serial.println("DHCP failed");

  ether.printIp("IP:  ", ether.myip);
  ether.printIp("GW:  ", ether.gwip);  
  ether.printIp("DNS: ", ether.dnsip);  

  if (!ether.dnsLookup(website))
    Serial.println("DNS failed");
    
  ether.printIp("SRV: ", ether.hisip);
}

void loop () {
  ether.packetLoop(ether.packetReceive());
  
  if (millis() > timer) {
    timer = millis() + 5000;

    // Reading temperature or humidity takes about 250 milliseconds!
    // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
//    float h1 = dht.readHumidity();
//    float t1 = dht.readTemperature();
    float h1 = 36.00;
    float t1 = 18.00;

//    float h2 = dht2.readHumidity();
//    float t2 = dht2.readTemperature();

    dtostrf(h1,5, 2, buff_h1);
    h1_string = String(buff_h1);
    dtostrf(t1,5, 2, buff_t1);
    t1_string = String(buff_t1);
    
//    dtostrf(h2,5, 2, buff_h2);
//    h2_string = String(buff_h2);
//    dtostrf(t2,5, 2, buff_t2);
//    t2_string = String(buff_t2);
    
    dht_string = "&h1=" + h1_string + "&t1=" + t1_string;
//        + "&h2=" + h2_string + "&t2=" + t2_string;
    
    
    Serial.println();
    Serial.print("<<< REQ ");
    ether.browseUrl(PSTR("/arduino/logger1.php?pwd=secret"), dht_string, website, my_callback);
  }
}

description formatting is completely lost -- related arduino forum post:: http://arduino.cc/forum/index.php/topic,138548.0.html