Help choosing laptop

Good afternoon,

I'm looking for a laptop that fills certain specifications. I'm hoping some of you folks would be so kind as to share ideas or personal experiences with laptops that fit the bill, or let me know if I'm asking for too much.

The biggest limiting factor is battery life. I spend 5-6 hours a day between classes/meetings without a power outlet when the ability to work would improve my quality of life, so I'm looking for a laptop that fits the following specs while also getting 5 or more hours of battery life.
Must multitask, ideally running college level powerpoint presentations, word documents, and a web browser at the same time.
I have had very poor experiences with XP and Vista, and very positive experiences with 7, so, 7 is a must.
Obviously, I need at least enough hardware to run 7 and fit the bill for the multitasking above.
Smaller than 15" is a bonus.

My initial hope was to spend less than 400USD. I'm realizing this is looking unrealistic? The cheapest I could find to do this was Toshiba 13.3" T235D-S1340. Will this do what I am looking to get done? Is there cheaper out there? Do I need a more expensive setup? Should I be looking at something like a macbook?

Thank you in advance!

Ryan

Have you considered a netbook, as they are excellent on battery life. They are low on performance, but should handle your uses alright.

Hi there! Thanks for the response!

I actually did consider those, specifically the Eee seashell 1215n. However, I've had several people tell me that those machines would not function reasonably with a large powerpoint, web browser, and word file open at once. Would you agree?

I'm fairly confident that 400 dollars is way below budget for something that will do what I am looking for. I'm having trouble finding anything cheaper than about 600USD that will do what I'm looking to do, and it's getting closer to the 750usd pricepoint of a refurbished macbook, which I would love, but again is so far above my initial 400 dollar hopes...