Computer can connect to Internet, but other devices can't?

[CrazyGuy]

I have a desktop computer, connected to a wireless router (Linksys Wireless B), connected to a DSL modem, connected to my DSL line. (Computer --> Router --> DSL Modem --> Line)

Yesterday everything worked fine. Today the computer can still connect to the Internet through the wired connection, but if I attempt to connect any devices through the wireless it fails. They find the access point but can't actually connect to the Internet. Everything is plugged in and I have not changed any settings. I verified the router's configuration and the WEP key I was using, everything is correct. All of the router and modem's activity lights are on, and green.

Any suggestions for anything else I might try? This is maddening. It was working perfectly yesterday and had been for months.

I'm willing to PayPal $10 to the first person who comes up with an easy solution that works and does not require purchasing anything.

Thanks for reading.
Thanks for the suggestions everyone. Powering down was the first thing I tried, before posting. When I went to try the other suggestions the issue seems to have automagically fixed itself. I hate this, it means I ended up not learning anything about the problem. But I appreciate the responses.