I have been using this phone since a month. Everything is amazing from its design to usability. I liked this phone because of its compactness and better screen resolution than its predecessor. The performance of 3D games are outstanding for an entry level phone from HTC. But its horrible to hook this phone to power twice a day even for a low use.
There is no solution to increase the battery life from either HTC or Android maker. It seems lot many users of this phone or version of android 2.3.3 are having this serious issue. Please refer to https://code.google.com/p/android/issues/detail?id=17383
To increase your HTC Wildfire S battery life, look for comment #318 in the above link.
Update the software to 2.3.5 so that you could get good battery life. I got 3 days for single charge with only on GSM calls and wifi, 3g disabled.