Bulk Data Generator provides a UI to generating sample data. Tested with SPE 4.3 on Sitecore 8.1.

bulk-data-generator-1.png

bulk-data-generator-2.png

bulk-data-generator-3.png

BulkDataGenerator-Demo.ps1

<#
    .SYNOPSIS
        Bulk generates items or users using the specified criteria.
#>

$dataTypeOptions = [ordered]@{"Item" = 1; "User" = 2 }
$props = @{
    Title = "Bulk Creation Tool"
    Description = "Choose what type of data to generate."
    OkButtonName = "Next"
    CancelButtonName = "Quit"
    Parameters = @(
        @{Name="Info"; Title="Warning"; Value="This tool is not intended for use on production systems."; editor="info";},
        @{Name="selectedDataTypeValue"; Value=1; Options=$dataTypeOptions; Title="What type of data should be generated?"}
    )
}

$result = Read-Variable @props
if($result -ne "ok") {
    exit
}

$dataTypeName = $dataTypeOptions.Keys | Where-Object { $dataTypeOptions[$_] -eq $selectedDataTypeValue } | Select-Object -First 1
$defaultCount = 10
$defaultItemNamePrefix = "Sample"
$contextItem = Get-Item -Path .
$database = $contextItem.Database.Name
$defaultRootItem = Get-Item -Path (@{$true="$($database):\content\home"; $false="$($database):\content"}[(Test-Path -Path "$($database):\content\home")])
if($contextItem.Paths.Path.StartsWith($defaultRootItem.Paths.Path)) {
    $defaultRootItem = $contextItem
}
$defaultDomain = "sitecore"
$domainList = (Get-Domain | Select-Object -Expand Name | ForEach-Object { $_ + "|" + $_ }) -join "|"

$defaultItemTemplate = Get-Item "master:\templates\Sample\Sample Item"

$props = @{
    Title = "Bulk $($dataTypeName) Creation Tool"
    Description = "Configure how the $($dataTypeName)s should be generated."
    OkButtonName = "Generate"
    CancelButtonName = "Abort"
    Width = 550
    Height = 450
    Parameters = @(
        @{
            Name="inputCount"; Value=$defaultCount; Placeholder="Enter the number of items";
            Title="How many $($dataTypeName)s should be generated?"; Columns=6;
            Validator = {
                if([string]::IsNullOrEmpty($variable.Value) -or -not($variable.Value -is [int])) {
                    $variable.Error = "The item count should be between 1 and 100."
                }
            }
        }
    )
}

if($dataTypeName -eq "Item") {
    $props.Parameters += @{
            Name="itemNamePrefix"; Value=$defaultItemNamePrefix; Placeholder="Enter item name prefix";
            Title="What should be the $($dataTypeName) name prefix?";  Columns=6; 
            Validator = {
                if([string]::IsNullOrEmpty($variable.Value) -or [Sitecore.Data.Items.ItemUtil]::IsItemNameValid($variable.Value)) {
                    $variable.Error = "The item name prefix is invalid."
                }
            }
    }
    $props.Parameters += @{
            Name="selectedrootItem"; Value=$defaultRootItem; 
            Title = "Where should the Items be generated?"; 
            root="/sitecore/content/"; Editor="Droptree"; 
            Validator = {
                if([string]::IsNullOrEmpty($variable.Value)) {
                    $variable.Error = "The item root is missing."
                }
            }
        }
    $props.Parameters += @{
            Name="selectedItemTemplate"; Value=$defaultItemTemplate; 
            Title = "Which Data Template should be used?"; 
            root="/sitecore/templates/"; Editor="Droptree";
            Validator = {
                if([string]::IsNullOrEmpty($variable.Value)) {
                    $variable.Error = "The item template is missing."
                }
            }
    }
} elseif($dataTypeName -eq "User") {
    $props.Parameters += @{Name="defaultPassword"; Value=""; Title = "Default Password"; Columns=6; Placeholder="Password (optional)"; }
    $props.Parameters += @{Name="selectedDomain"; Value=$defaultDomain; Options=$domainList; Title = "Which domain should be used when generating Users?"; Columns=9; }
    $props.Parameters += @{Name="enableUsers"; Value=$false; Title = "Enable Users"; Columns=3; }
}

$result = Read-Variable @props

if($result -ne "ok") {
    exit
}

if($dataTypeName -eq "Item") {
    $rootItemPath = $selectedrootItem.FullPath
    $childCount = $selectedrootItem.Children.Count + 1
    for($index = $childCount; $index -lt $childCount + $inputCount; $index++) {
        New-Item -Path $rootItemPath -Name "$($itemNamePrefix)$($index)" -Type $selectedItemTemplate.Paths.Path
    }
} elseif($dataTypeName -eq "User") {
    $firstNames = "Michael Rebecca Adam Jason Martha Alan David Khris Robert Chris Steven Peter Matthew Mark Luke John Thomas Sarah Lisa Martha" -split " "
    $lastNames = "West Smith Johnson Williams Brown Jones Martinez Thompson White Wilson Harrison Lee Beckham" -split " "
    
    for($index = 0; $index -lt $inputCount; $index++) {
        $first = $firstNames[(Get-Random -Maximum $firstNames.Count)]
        $middle = [char](65 + (Get-Random -Maximum 26))
        $last = $lastNames[(Get-Random -Maximum $lastNames.Count)]
        $randomId = Get-Random -Maximum 9999 -Minimum 1000
        $userId = "$($first[0])$($middle)$($last)$($randomId)".ToLower()
        $commandProperties = @{
            "Identity" = "$($selectedDomain)\$($userId)"
            "FullName" = "$($first) $($middle) $($last)"
            "Email" = "$($userId)@testdomain.com"
        }
        
        if($enableUsers) {
            $commandProperties["Enabled"] = $enableUsers
            $commandProperties["Password"] = @{$true=[System.Web.Security.Membership]::GeneratePassword(10,3);$false=$defaultPassword}[[string]::IsNullOrEmpty($defaultPassword)] 
        }
        New-User @commandProperties
    }    
}

Feedback:

• Check for existing username
• Add "real name" to the user
• Add option to enable/disable users
• Add option to specify default password
• Check for context menu selected item before defaulting to the home item
• Add validation check for the prefix
• Add validation for the template name
• Add validation for the root path