I got ticked off at the way my promo was expensive to produce and easily discarded or abused so I searched for something better.
Lately I've been making my own business card CD's. They can be purchased from any CDR house such as
http://www.cdrom2go.com/ and burned on standard CD burners. It helps if you have a printer that can print directly on the bus card CDR also such as the ones at
http://www.ezcdprinter.com. Each bus card CDR holds up to 50MB - that's one five minute song at 44.1k 16-bit stereo wave file on average. I put together a montage of songs for a five minute demo, and I've created special wedding demos, jazz demos, etc for each market I'm after. They are cheap to mail also - I recently did a big hit on all the wedding coordinators in my area by sending them "invitations" that contained my wedding bus card CDR. Business card CDR's cost about 60 cents each.
If you have the tech chops then you could create your own multimedia presentation on these too but sometimes asking your employer to stick your demo CD in a computer is reaching over their heads. My bus card CDR's play on regular CD players.
If my business card CD's don't impress my prospects, they aren't the people I want to work for anyway. These look great and are a cool promo item. Easy to carry too. Once the client calls you back then you can give them the 8x10, songlist and other things they'll want.