James, this site has a fantastic amount of useful information regarding batteries, how to cycle them, how to charge them and how long they'll last. Check out:
How to prolong lithium-based batteries for Lithium-Ion batteries.
Just for curiosity, how long are people batteries lasting?
I shot 1050 shots last weekend, all JPEG, lots of reviewing, mostly Tv mode, no flash. After that the battery was still reading full! What's more the ambient temperature was about 10-16 degrees Celcius, that normally halved the life of my Ni-Mh's out of the *istDL.