I use a Duratrax Pirannah RC Car charger. It peak charges NiMh or NiCd batteries to the maximum power output, and allows you to adjust charging current to charge a set of batteries quickly. I charge AAA 800Mah batteries at about .75 amps, and they charge up from depleted in less than an hour. The charger has a digital readout, so you can monitor the charge, and see exactly how many milliamp hours you've put in the battery. You can find "peak detection" RC chargers on EBay. Don't charge a AAA battery at more than 1 amp, or it'l overheat, and possibly stop working (or piss out all the electrolyte, if you're realy unlucky!)
I sold all the RC stuff except the charger, and I never buy disposable batteries. Just run off to Radio Shack, and get battery holders of the size and number of cells you need, and you're good to go. I keep my remote controls, all my lasers and flashlights, and my telescope electronics happy on rechargables.
One serious tip with rechargables.... NiMh batteries should never be run down completely, if you're using more than one cell in a device. What happens, is one cell depletes before the other, and the live cell damages the dead one. I figure on keeping a couple sets with me, and if I notice the laser getting a bit dim - change batteries immediately.