I am using my (wireless) Magic Mouse for 4 years now. I use recheargable batteries which need to be replaced/recharged every 2 months.
My letter E on my keyboard stopped working, so I replaced it with a*Z-Board gaming keyboard. I stopped using my wireless mouse a long time ago because I got tired of changing the batteries.
Man, what are you guys doing that drains your k/b and mouse batteries in 2 weeks?!
I have rechargeable NiMH batteries for both the wireless k/b and the magic trackpad. I have a couple of sets, so that when they get low I can just swap them over and the second set can charge up without me being without a keyboard.
Bear in mind NiMH batteries have a relatively high self discharge rate, so you can't just charge them up full and then keep them in a drawer - charge them just before you need them.
When my k/b or trackpad says it is down to about 10% battery I charge up the second set and then swap over when they charge to full.