DO NOT run Lithium-ion completely dead. some will go "open" and not even accept a charge for several hours (if the protection circuit resets) or sometimes not at all.
I bought this off of eBay and it is an OEM Motorola battery with a well made charger.... I have it on my Droid now and I can't tell which was the orogonal that came with my Droid... they both last all day with a decent amount of web browsing and listening to music, on top of normal phone use. Highly recommend this, and it arrived in only about a week instead of the 14 days they overestimate.