I want to email my iTunes playlist to a friend--both the playlist order and the actual songs it includes. Is there a way to do this?

Definitely. Begin with the playlist, which iTunes lets you export. Select your playlist in the iTunes sidebar and go to File > Library > Export Playlist. A dialog will let you name the playlist file and choose where it’s saved. For Format, choose XML.

But that XML file is just the list of songs and their order, not the actual song files. To get those, click on your playlist in the sidebar again, select all the songs inside it, and drag them over to the Desktop, which creates copies of each song in its original format. The song files won’t be moved out of your iTunes library--they’ve only been copied. Toss them all in a new folder, add the XML file with the playlist information, then right-click the folder and select Compress to make the folder into a zipped archive.

Select the songs in your playlist and just drag 'em over to your Desktop for a copy of the file.

If that archive is small enough to email, go for it. Gmail, for example, caps email attachments at 25MB, but our 105-minute playlist of MP3s was 184MB after we zipped it. So you might have to split up the files into a couple smaller folders first, and compress those instead. Or you can use a service for sending larger files, like YouSendIt (www.yousendit.com) or Megaupload (www.megaupload.com).
 
When your friend gets everything, they can drag the song files onto the iTunes window or Dock icon to add them to the iTunes Library. Next, they should select File > Library > Import Playlist and import your playlist’s XML file, which will re-create the playlist in the iTunes sidebar. Um, and those fire-breathing music-industry lawyers would like us to remind you that piracy is illegal. Betcha didn’t know that.