Well, you'll need to tell us a bit more than that:
-Link us to your laptop model or give us your current specs
-How much are you willing to spend?
-What do you want to speed up? Different parts will help in slightly different ways.
-What OS are you using?
In a laptop your only easy upgrade options are ram and the hard drive. A Solid state drive will provide a performance boost in application load time and, well, anything else that exchanges data with the hard drive. A ram upgrade will only help up to 768MB in windows xp. I wouldn't really bother if you already have 512mb. If in your situation it can provide more performance, it is a much cheaper upgrade option.