Some people may disagree with me, but I can see rubberbands working great in restaurants. Depending on how long you're working, you'll probably need a bunch, but there's a few good DVDs. I'd recommend Band Shark by Dan Harlan and Extreme Rubber Band Magic by Joe Rindfleisch. A good out in case a band breaks is Jumper, also by Joe Rindfleisch. Since there may be some people allergic to latex, get non-latex bands here:
http://www.dykemarubberband.com/specialty_rubber_bands.php . Size 19 bands are what most rubberband magic is done with, and it's 1,750 for only 8 bucks - not to mention they're stronger than most latex bands.
H&R magic books is currently having a sale, so you might be able to pick them up on sale (used) here:
http://www.magicbookshop.com/
EDIT: Reverhart has a good point on set-ups. There are a few broken and restored band effects that require a set-up on Extreme Rubber Band Magic, but they literally take 5 seconds to set up and you can wear the band around your wrist normally. Setups aren't something you'll need to worry about too much if you plan on doing any of the effects (if, of course, you even like band magic).