I have the basic LimeWire 4.9.7 version. When I decide to upgrade, can I keep the version I have now stashed away deep in my files or will it disappear when the newer version is installed? I would like to keep the version that I have now just as a back-up in case the newer LimeWire's aren't to my liking.

If you do nothing and install the new version it will wipe out the old version. The safest way on Mac anyway and I have 3 hard drives , is to copy the old version, move it to another drive, and for good measure rename it. I tried moving a copy from applications to the desktop and that got deleted, perhaps if I had renamed that it would have been alright. You can experiment a bit to find out what works but save a copy either on another drive and back it up on CD for good measure. I made sure I did, in my brief sojourn as a beta tester .... I hope poor old Deacon got his asprins after.

I'm stubbornly sticking to 4.8.1 until I hear the rave reviews....