I lived in the US for about 1 year on a L1 visa. I moved out in 2009 and filed taxes for that year. Do I have to file taxes for 2010, if I didn´t live in the US?
THANKS!

Probably not. If you filed as a resident for 2009, you should have submitted a Residency Termination Statement. The IRS position is that if they do not get this statement, you remain a resident and thus liable for U.S. income taxes, but if you worked outside, the IRS has no way to know what you earned.

If you did not live in U.S. in 2010 and do not have any U.S. income, you do not file the tax return.