Be CarefulCouple of things you should know. One is that Acer will clock the same card (ie: the x700) to different frequencies in different notebooks. Which means that the exact same graphics card in your model (ie: a TravelMate 8104) might be clocked different from the one in a Ferrari model.
So don't expect that all notebooks come clocked with the same speeds, just because they have the same graphics card in them. As a general rule, Acer clocks the graphics cards in Ferraris much higher than in other notebooks. Think of it as their way to turbo charge the notebook that they want people to notice the most.
Your options are to undervolt, and over clock. But if you want to increase the graphics power of your notebook, it will become more difficult to increase battery life at the same time. Be careful, as you can run into some major problems doing this to any notebook pc. I suggest doing some searches on undervolting (will help save some battery life), and overclocking (will help improve gaming experience... or at least, benchmarking results).
Personally, I suggest not overclocking at all. You can do some major damage if you're not already experienced in doing this. I've seen people do permanent damage to their computers by overclocking, and the results gained were often minimal. Just leave that part alone, and enjoy what you've got.
As for battery life, I also don't recommend undervolting, as there are easier, simpler things you can do that will make a difference as well, and still keep your system very stable. If you want to try undervolting, go ahead and give it a shot, as it does make a difference.
What I really recommend doing is pay attention to how your computer reacts when you unplug it. You have a really great tool in the "ePower Management" program that Acer provides in all their notebooks. In fact, when I read up on Windows Vista, most of what they claim to provide as new power-saving features are already taken care of by Acer's awesome program! Yay for Acer!
Basically, set your notebook up so that any power-eating system feature is turned off when you unplug. For example, have it set so that your Bluetooth turns off, WiFi turns off, etc, unless you use those things. Since you can set it to do this automatically, you don't have to go through and turn all these things off every time you want to save on battery power. Set it once, and adjust as needed.
Also (and this will make a big difference), set your graphics card up so that it's at the lowest performance level when on battery power (I don't have my notebook handy, but the option is in the ATI Catalyst Control Panel properties). Basically, your graphics card eats up a lot of power. Set it to be as battery-friendly as possible when on battery power, and you can easily gain 30 minutes of battery life (I know I did).
If you game when on battery power, then you might not want to set it this way, but I've set mine to be as powerful as possible on battery power before (to play CoD), and it ate up my entire battery in 45 minutes. Not bad, for a great gaming lunch break, but still not what a normal user wants, when they're not gaming. Also, set your screen to as dim a setting as is comfortable, when on battery power. This part changes with your environment, so just adjust as needed. There are some other tricks as well, and you can find them by doing some searching around both here at the awesome NBF.com, and also on Google or another search engine.