I have never gotten anything close to 24 hours. So many obstacles are in the way such as phone calls, data usage, plain ol' usage of the device itself, signal strength, et cetera.
An extended battery helps a lot. I have an extended battery in my Centro and I can go about 8 hours before it starts getting seriously hungry. As a result and as mentioned above, mine is fed throughout the day. Your usage means the battery life will vary. The batteries used in these devices DO NOT like to be allowed to die and battery life will suffer - feeding makes them happy, starvation kills 'em (DO NOT read politics into this!!!!!).
PowerHero from
www.hobbyistsoftware.com may be of interest to you.
Ben