Users of Apple's GarageBand 3 (part of iLife '06) are familiar with its built-in "podcast studio." The studio is complete with pre-made jingles that you just drag-and-drop into a GarageBand track. With so many podcasts made with GarageBand out there, you might start to notice that those same default jingles are used in many podcast episodes.
Subscribers to Apple's .Mac suite of services ($99 per year) can download dozens of additional jingles for free. Just log in to your .Mac account, click Member Central in the list along the left side of the page, and then click Free jingles + voiceovers. Listed are jingles in nine different categories, including Alternative Rock, Blues, Cinematic, Country, Electronic, Jazz, Rock & Pop, Urban, and World. There's over 800MB in free music for podcasts! Downloads from .Mac's Member Central are usually available for a few months. If you are a .Mac member, download them soon before they disappear.
Unfortunately, you have to install each of the .Mac Podcast Packs separately, but once they are installed, you have access to great podcasting music. Just choose Show Loop Browser from GarageBand's Control menu. Many of the jingles have different lengths, depending on your needs.
Also included are 17 professional voiceover tracks by Joe Cipriano. You're sure to recognize his voice as he's done voiceover work for broadcast networks like ABC and FOX. His recordings are short segments like, "Now, welcome back to the show," and "Coming up next in our show..."
With the 136 new sound files included in the .Mac Podcast Packs, your podcast can have jingles different from the defaults everyone else is using.