The 2010 401(k) plan contribution limits are unchanged from 2009:
2010 401(k) Contribution Limits
The 2010 401(k) contribution limit remains $16,500. If you reach age 50 by December 31, 2010, then you can contribute an additional $5,500, for a total contribution of $22,000. That amount is also unchanged from 2009. (For the year 2008, the base contribution limit was $15,500 with a possible $5,000 catch-up contribution, so the potential total contribution for someone 50 or older was $20,500.)
Note that both the limits also apply to 403(b) and Section 457 plans. The SIMPLE IRA contribution limit is $11,500.
Your employers restrictions may cause your individual contribution limit to be somewhat lower. Possible causes include a cap on the percentage of pay you are eligible to contribute and your employer not yet allowing for catch-up contributions.
If you can afford it, contributing up to the limit is a great idea, since a 401(k) plan is one of the best ways to save for retirement.

