Ok this site helped me so i will put the info back out there.
For those of you running vista, you need to click on start.
Now in the start search box, type folder options.
You will see it at the top of the list.
Click on it.
Now Click on the view tab.
One of the selections in this view will be HIDDEN FOLDERS.
Make sure that SHOW HIDDEN FILES AND FOLDERS is selected.
Right below that make sure HIDE EXTENSIONS FOR KNOWN FILE TYPES is unchecked.
Hit APPLY.

Now go to Start again. In the very top right hand corner of that window you will see a name of some sort. Probably your own. It's w/e you named your computer. Click on that.
Now you should see a sorta ghostly looking folder called AppData.
Click on that.
Click on Roaming
Click on Limewire
Click on Themes
Now this is the folder you will save your zipped themes.
From here you will right-click on any zipped folder that you save here and rename it. Literally right-click and scroll down that box until you highlight rename. A box will form around the current file name. Press the right arrow key. press backspace until you see .zip disappear. type .lwtp. Press enter.
Your new file should read whatever.ltwp.
It used to read whatever.zip
Now you can open limewire and go to view, and go to apply skins and then select w/e skin you want.

Ok. I cant apply my skins. they are listed in the menu but it says that they do not exist! help!

THANK YOU, CAVALRY!!!!... I read the tittle of your post and i laughed, but then i said, ok, let's see what he's got.... And I finally got it!. I was extracting the files and trying to convert them to .lwtp . Dumb!
So, thank you, you were very helpful!!!

Thanks for the great info... Worked great... Good Job!!!

I think I'm having a problem when I go to rename it. I think I'm really confused about that part...haha. So if someone could possibly break down that part for me, I'd really appreciate it! I'm kinda stupid when it comes to these things.

i got partway through the process and ran into little problem. i got to the part where you said "Click on Roaming" then there wasn't a limewire folder!!!! WAT DO I DO?????

hay thanks heaps your help was definately needed! lol

ah thank you so much. I could not figure out what I was doing wrong!

It was all going good until I got to go AppData. I couldnt find it anywhere. Do know what i should do? HELP!!!

See whether this link helps to find it (has screenshots). Remember that App Data's hidden by default: LimeWire Pref Folder in Vista