You have tried turning your computer off???
Which OS and version of Lr3?
Hi Rick. Don't worry, we'll figure it out somehow!
I'm guessing from the blue icon that it's some flavour of Windows.
Restart your computer as Geoff suggested.
If it still doesn't work, try holding down the Ctrl key while you open LR, and see if it'll bring up the dialog that lets you choose a catalog. If it does, let it start a new catalog temporarily, and see if that will open properly.
Then report back, and that'll give us a clue on what to do next.