I found out the problem. Thanks for the interest.
We have an iMacG5 OSX 10.4. My husband and I have separate "accounts" and each use Safari. Suddenly today I cannot get onto Safari. The icon is still there in the dock, but it doesn't open and I can't find it in Applications. My husband's Safari opens fine. So what happened?
I wouldn't mind using another browser actually, but I had bookmarks on Safari that I would like to save. I got onto Netscape to send this request, so obviously the connection to the net is OK. I will say it seems like the computer is a little slower to respond to clicks recently. Last week the plug was loose and the computer shut down suddenly twice. Could that have affected everything this late?
I couldn't find anything like this on the Mac site's forums. Thanks to anyone who can advise. S

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic