Wanted- A Bicycle
At 250 pounds, I would think that most bikes sold at retailers like Wal-mart, Target, etc would work for you. However, I would suggest contacting, in person or email, and independent local bicycle shop and talking to an expert (as opposed to a retail associate who happens to be working in the sports departement that day). They should be more than happy to help you determine the proper fit, model, etc - that's part of good customer service!
If you needed a weight capacity of up to 500 pounds, my suggestion would be to visit www.livingxl.com as their latest catalog actually features bicycles on the cover. They've got lots of quality outdoor/fitness gear for large folks. Their stuff is pricey, but it's good quality. Of course, all of it can be used once you lose more weight, too - it's just that the sleeping bags would be roomier, camp chairs sturdier, etc. If you swim, they've got some great looking suits in the clearance section that were originally $100.00 now for $14.95! My motto is buy quality - but on sale, or better yet, clearance!
Amy