What to do with my Bitcoins?
You can find lots of Bitcoin-related services on the Trade page in the Bitcoin Wiki.
Check out Bitcoin's largest online auction house at BitMit!
An increasing number of physical stores, restaurants and other venues accept Bitcoin as well. Check Bitcoin Travel and Bitcoin Navigator to see if there are any in your area.
Turn your Bitcoins into gift cards from Amazon, Barnes & Noble, iTunes and many more at SpendBitcoins.com. Or get gift codes for services like XBoxLive, PSN or iTunes instantly online at Bitcoincodes.com.
Buy music, ebooks, wallpapers and other downloadable content at CoinDL!
You might also want to check the Bitcoin Marketplace forum on Bitcoin.org.
Over-the-counter trading is being done via IRC chat in Bitcoin OTC (#bitcoin-otc on Freenode).