Google app script for hack and tell. Probably a dupe.

hackandtell.js

var PENDING_INVITE = '#fff2cc';
var INVITED = '#00ff00';
var CONFIRMED = '#ffff00';
var NOT_THIS_TIME = '#00ffff';
var NOT_THIS_TIME_SENT = '#4a86e8';

function markPerson(person, newtyp) {
  var nameCell = person['range'].getCell(1, 1);
  nameCell.setBackground(newtyp); 
};

function findPeopleByType(typ) {
  var ranges = []
    , sheet = SpreadsheetApp.getActiveSheet()
    , rows = sheet.getDataRange()
    , numRows = rows.getNumRows()
  
  for (var i = 1; i <= numRows - 1; i++) {
    var range = sheet.getRange(i, 2);
    if (range.getBackground() == typ) {
      var range = sheet.getRange(i, 2, 1, 4)
        , values = range.getValues();
      ranges.push({
        'range': range
      , 'email': values[0][1]
      , 'name': values[0][0]
      , 'desc': values[0][3]
      });
    }
  }
  

  return ranges;
};

function getCommentary(range) {
  var commentary = SpreadsheetApp.getActiveSpreadsheet().getRangeByName("Commentary");
  
  Logger.log(commentary.getColumn() + ': ' + commentary.getValue());
  
  return commentary.getCell(range.getRow(), 1).getValue() || '<to be written>';
}

function generateWrapupEmail() {
  var presenters = findPeopleByType(CONFIRMED)
    , buffer = [];
  
  buffer.push('# Round <insert number>: <insert name>');
  buffer.push('Hello hackers,');
  buffer.push('Thanks to <insert host>. <insert rest>');
  
  buffer.push('## Projects Presented (in pseudo-random order)')
  
  for (var i = 0; i < presenters.length; i++) {
    var s = '### ' + presenters[i].name + '\n\n';
    s += getCommentary(presenters[i].range);
    s += '\n\n* []()';
    
    buffer.push(s); 
  }
  
  buffer.push('## Announcements and things to watch out for...');
  buffer.push('Happy hacking,');
  buffer.push('Andrew and James');
  
  doOutput(buffer.join('\n\n'));
};


function formatYesEmail(name, desc) {
  return "Hey " + name + ", \n\n" +
    "You've been selected to present at Hack and Tell. Please let us know if you can still make it!\n\n" +
    "In case you don't remember, this is what you told us:\n\n'''" + 
     desc +
    "'''\n\n" +    
    "Happy Hacking,\n\n" +
    "Andrew and James";
};

function formatNoEmail(name) {
  return "Hey " + name + ", \n\n" +
    "We couldn't confirm you for a presenter spot this time. Sorry! We have tried to RSVP you, however, if you weren't already.\n\n" +
    "Happy Hacking,\n\n" +
    "Andrew and James";
};


function invitePendingPresenters() {
  var people = findPeopleByType(PENDING_INVITE);
  
  for (var i = 0; i < people.length; i++) {    
    GmailApp.sendEmail(people[i]['email'], 'Presenting at Hack and Tell :)', formatYesEmail(people[i]['name'], people[i]['desc']), {
      'from': 'apgwoz@gmail.com'
    , 'cc': 'jdennis@gmail.com, apgwoz@gmail.com'
    , 'name': 'Andrew "AppBot" Gwozdziewycz'
    });
    
    markPerson(people[i], INVITED);
    
    Logger.log('Sending ok email to: ' + people[i]['email']);   
  }
};

function rejectPendingPresenters() {
  var people = findPeopleByType(NOT_THIS_TIME);
  
  for (var i = 0; i < people.length; i++) {
    GmailApp.sendEmail(people[i]['email'], 'Presenting at Hack and Tell :(', formatNoEmail(people[i]['name']), {
      'from': 'apgwoz@gmail.com'
    , 'cc': 'jdennis@gmail.com, apgwoz@gmail.com'
    , 'name': 'Andrew "AppBot" Gwozdziewycz'
    });
        
    markPerson(people[i], NOT_THIS_TIME_SENT);
    Logger.log('Sending reject email to: ' + people[i]['email']); 
  }
};

function collectEmails(typ) {
  var people = findPeopleByType(typ)
    , emails = [];
  for (var i = 0; i < people.length; i++) {
    emails.push(people[i].email); 
  }
  
  return emails;
};

function doOutput(thing) {
  var cell = SpreadsheetApp.getActiveSpreadsheet().getRangeByName("OutputField").getCell(1, 1);
  cell.setValue(thing);   
};

function outputConfirmedEmails() {
  doOutput(collectEmails(CONFIRMED).join(', '));
};
           
function outputInvitedEmails() {
  doOutput(collectEmails(INVITED).join(', '));
};
           
function outputRejectedEmails() {
  doOutput(collectEmails(NOT_THIS_TIME_SENT).join(', '));
};

function onOpen() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet();
  var entries = [
    {
      name: "Invite Pending Presenters"
    , functionName : "invitePendingPresenters"
    },
    {
      name: "Reject Not-This-Time Presenters"
    , functionName : "rejectPendingPresenters"
    },
    {
      name: "Get Confirmed Emails"
    , functionName: "outputConfirmedEmails"
    },
    {
      name: "Get Invited Emails"
    , functionName: "outputInvitedEmails"
    },
    {
      name: "Get Rejected Emails"
    , functionName: "outputRejectedEmails"
    },    
    {
      name: "Generate Wrapup"
    , functionName: "generateWrapupEmail"
    }    
  ];
  sheet.addMenu("Hack and Tell Tools", entries);
};