Battery Life

I took the next step and just purchased my first SLR camera the 30D. My question is how many shots can be taken with the battery that comes with the camera not using the flash?With my other cameras I've always had two batteries. One in and one fully charged ready to go. Should I do the same with this camera or get the BG-E2 battery grip? How many shots or how long does this battery last? Would it be easier to have 2 or 3 of the small batteries ... less weight or the BG-E2?
Peace MJEXP

I (we) have no idea what/when/where/how you shoot. I have 2 20D's equipped with BG - grips. Advantage = larger hand grip area + more weight to stabilize/balance + never ever have to consider battery drain (all day 900-1000) and I can chimp away all day with no concern .

Battery gettig low? - just pull one and recharge as you continue to shoot.

Disadvantage = haven't found one yet.

Regardless if you get the grip or not, I'd recommend having at least one spare battery on hand. According to Canon's specs they state 1100 frames with no flash, 750 frames with 50% flash. That being said, batteries have a knack for dying at the most inoportune times. Always carry a spare.

Welcome to the forums MJEXP, Another factor to consider is the temperature, if it's cold they have a habit of dying a lot quicker. Constantly looking at what you have just taken ('chimping') also kills battery life. You should certainly get a few hundred shots on one battery.
As previous posters have said, ALWAYS carry at least one spare!

Get the battery grip and battery life will not be an issue, plus it will feel better in your hands

Definitely get a spare couple of batteries, but unless you like to shoot at 5fps all the time, you are very unlikley to run out of batteries on even a busy day shooting.
check out the accessories page, there is a sticky there for third party batteries, of which Stirlingtek come out right at the top. they sell great batteries, identical to the 511, with higher mAh rating so they actually last longer, and for a fraction of the price of the Canon batteries. Their service is superb as well. I've got 2 stirlingtek batteries in my bag as back up though so far I've never needed a back up, it's good to know they're there!