When I'm at work, I just keep my phone plugged into a USB cable connected to my computer. At home, I keep it plugged in if it's setting on the kitchen counter.
I use to try and get a full day out of my phone, until I did some reading on battery technology. The charger circuits and batteries in these phones are made to keep the batteries topped off without overcharging. Additionally, the batteries really aren't designed to "deep cycle" over and over again.
By keeping the phone plugged in when I can... I think I'll get a little more life out of the battery pack in general, and I don't need to worry about running out of juice mid-day.
-SF