I might need a new laptop...

...since my 6-year-old Thinkpad occasionally crashes when it gets touched/stressed in certain places. The screen's kinda crapping out too. Budget's a bit tight, only about $800. Any recommendations? I like the fact that my Thinkpad's only 4lbs, so I don't really care for anything huge unless it has the screen/features to back it up. (ex. not an Inspiron 1100) I'm willing to get an older laptop; I'm thinking about a thinkpad T20 or T30 or possibly an older Vaio 505 series, but maybe I should go with something else.