[NutmegCarrera]

+1 on the Nashbar and Performance reccomendations. I've used them both successfully since the mid-1980's. They get you through for the majority of the run-of-mill tire, tube and component type stuff. I try to avoid their "house brand" parts, components, clothing and tires - as all are very appealing to the pocketbook, but can come in with less than desirable performance.

As for the higher-end stuff, Colorado Cyclist is a great source. Look to them for higher end clothing, but watch for sales during the off-season. Their retail prices are usually still better than bike shops (which typically suffer from poor selction, even at those prices). A similar place is excel sports, Boulder.

If you're looking for some odd, small, or out dated widget - there's a little-known place called loose screws bicycle parts. Seriously! These guys can fix you up if you're looking for an old derailluer part for a nuovo or super record.

Keep turning the cranks!