I needed to make some rubber stamps of my own recently. You can design your own stamps and email them to a company called Rubber Stamping Across America (or something like that.) Their website is:
www.rubberstampit.com. You can design a whole 7" x 9" sheet for $18.00. I ordered mine, but have not cut it out and stamped with it yet. It does not look like the same quality you'd get from a regular stamp store, yet I think it will do the job I need them to. I'll let you know after I try them. Anyway, it was a lot cheaper than the $60.00 that I paid to Office Max for 5 stamps!