The Pila charger is really nice, but I can't bring myself to spend that much on a charger. The Trustfire TR-001 and TR-003 chargers work very well and arnt expensive. The TR-003 can charge 4 batteries at once and the TR-001 charger can charge 2 at once. I have the TR-001 charger and it works very well and charges the batteries pretty fast.
Many ecig vendors sell it for $10-15. If your willing to wait 2 weeks for it, I got mine off eBay for only $8.40 with free shipping. It's def cheaper than you'll find it anywhere else, but it does ship from china so that's why it takes like 2 weeks to get to you