Granted, you have a big exclusion but if you purchased your house 30 years ago you'd probably owe Capital Gains Tax

In 2009 you have a $250,000.00 exclusion for a single person and a $500,000.00 Exclusion for a couple. Most would not have to pay taxes but If you bought your house by 'yourself' in 1980 for $25,000.00 and it's worth $500,000.00 now, you would pay around 45% on $225,000.00 or about $100,000.00 in Capital Gains Tax.

$100,000.00 could be a nice cruising boat.