Take pedals for instance. My favourite set of pedals are a pair of VP BMX style platform pedals (a bit like the Shimano DX pedals of yore). I've had a set for about 3 years now and they've been used and abused on the MTB and the commuter - suffered jetwashing, crashes and day to day use in disgusting weather. As a result they've become a little rattly and unhappy - until today.
Inspired by this article on Bike Radar I decided to get busy with the 5mm drill bit and inject some greasy new life into my pedals. However the Bike Radar article requires you have a proper grease gun. However I found that a disposible oral syringe did the trick. I drilled a 5mm hole in the plastic end cap of the pedal and syringed large amounts of grease into the pedal until it blew it's end cap off. I pushed the end cap back snug and voila - smooth pedals and probably an extra year of happy pedalling.
As you may have guessed by now I'm allergic to spending money when I don't have to!