Ok everyone.. im in the market for a laptop for uni next year as well and also want to play half life 2 on. I think I found the best solution.
You can find ALOT of info on laptops at
http://notebookforums.com/
For those of you after alot of battery life go to
http://digitalstar.com.au and check out the 'Centrino' line of laptops. The one I will probly get is the CL56.
It has PM 1.7Ghz (much cheaper than 2Ghz and VERY little performance difference)
1024MB Ram (more ram the better eh?)
128MB 9700 ATI graphics (only thing better is Gforce PCI express, big $$)
60gig 7200 HDD (Yes hdd speed does make alot of difference for large files like divx movies, mp3, pictures etc)
a SVGA+ 15" screen (high resolution)
Build quality is great.
XP Pro
4hrs battery
all this for about $2700
Im buying mine when the shop opens back up on 4th of Jan.
There is a review
here. The CL56 is sold in America under the name Sager and Compal, so if you ever see a review or coment about those they are talking about the same laptop.
If you really need battery life there is a laptop there that says it will last up to 7hrs!! that should be more than enough for a lecture or study group etc
Another thing.. Warranties are very important, computers DO break down, even the expensive ones can have problems like dead pixels in the LCD screen and keyboards and those finger pads not working. Where ever you buy your laptop from get at least 2 years warrenty. I am goin to get a 3 year warrenty and at digital star it costs like $150 very worth it.
Thats my 2 cents.
Happy shopping