VisorCentral.com (http://discussion.visorcentral.com/vcforum/index.php)
- Springboard Modules (http://discussion.visorcentral.com/vcforum/forumdisplay.php?forumid=10)
-- bar code scanner / portable cash register / credit card swiper (http://discussion.visorcentral.com/vcforum/showthread.php?threadid=5028)

This idea would be great for flea marketeers, sidewalk vendors, & even small retailers who can't afford the more expensive POS systems. Bundle it with pocket Quicken or some other 3rd party software and I think you've just seduced a whole new class of palm os users.