Federal tax withholding

I am one of those people who would rather get a nice refund back at the end of the year. Many people will say that you are only giving an interest-free loan to the government if you get a large refund. To me it is a forced means of savings. I expect to get about $5,000 back from my federal tax refund and another $1,000 back from my state refund. The vast majority of that money is earmarked to payoff my credit cards balance which now sits at $5,880 at 0% interest and will be closer to $5,000 when I get my tax refunds. Anything leftover will go into my emergency savings or even my Roth IRA. I am considering changing my withholding for 2008 so that I can increase my 401k investments. I thought that I would be able to max out my 401k withholding this year but with the monthly credit card payment I just have not been able to. I cannot wait to get my hands on that money.