Check that all the "dangerous" things are tight (but not too tight), such as:
cranks
pedals
handle bars & stem
brakes (where they attach to the bike, and where the cables are held*)
seat post
STI levers (where they screw onto the bars)
wheel skewers
and make sure the tires haven't gone dry and crusty on the sides
*It's easy to over tighten and break the bolts that clamp the brake and gear cables. These don't have to be very tight; only tight enough to (obviously) hold the cable.