Download hrej podcast

$rssXml = New-Object System.Xml.XmlDocument
$rssXml.load("http://www.hrej.cz/podcasty/podcast.xml")
$seznamMp3 = $rssXml.SelectNodes("//rss/channel/item/guid[starts-with(.,'http') and substring(.,string-length(.)-2) = 'mp3']")
foreach($mp3 in $seznamMp3)
{
    Write-Host $mp3.'#text'
    Invoke-WebRequest -Uri $mp3.'#text' -OutFile ('c:\temp\'+($mp3.'#text').substring($mp3.'#text'.LastIndexOf('/')+1))
}