Saving money with third-party accessories

I'm sitting here looking at my month-old power adapter for my iBook and smiling. It's been working perfectly, and it cost less than half as much as the official version that I bought to replace my broken adapter the last two times.

It came down to 1) doing my research and 2) planning ahead. The first time around, I didn't even realize there were third-party adapters. By the second time the adapter went on the fritz, I was researching to see if I could buy the official version at a better price, and found out about my other options through that process... but I didn't pull the trigger in time, the adapter died completely, and I had to run out to the Apple store and grab a replacement on the spot. But this time, at the the first signs of my adapter starting to fray, I double-checked my research and then ordered up a well-reviewed, cheap alternative, so that when the old one stopped working I had the new one at my side already.

Don't settle for the official accessories for your items without doing the research to find out if you have good alternatives that are more affordable! Do you have any other good examples of third-party/alternative items you've found that helped save money?