How can I file my taxes without my w2 forms?

Do you have your most current 2007 pay stub?
You might be able to use that.

Yes, you can but you should not. If your return is not accurate you may have to file amended return and even pay interest and penalty.
If you are unable to get W2 from employer, call IRS. Also read Missing Your Form W-2? (http://www.irs.gov/newsroom/article/0,,id=106470,00.html)