Somebody's where.exe implementation as powershell ;)

Where.ps1

function where-is($command) {
    (ls env:\path).Value.split(';') | `
        where { $_ } | `
        %{ [System.Environment]::ExpandEnvironmentVariables($_) } | `
        where { test-path $_ } |`
        %{ ls "$_\*" -include *.bat,*.exe,*cmd } | `
        %{  $file = $_.Name; `
            if($file -and ($file -eq $command -or `
			   $file -eq ($command + '.exe') -or  `
			   $file -eq ($command + '.bat') -or  `
			   $file -eq ($command + '.cmd'))) `
            { `
                $_.FullName `
            } `
        } | `
        select -unique
}

Much prettier.. :D