i am willing to bet that the reason you are not seeing this free utility for exporting transparent gifs anymore is exactly because of unisys, as someone said they didnt like people exporting their gif format without them cashing in on it, so you see it would be silly for someone to offer a free service to do this if they legally have to pay unisys for doing it

for the same reason such things as the perl GD graphics library (which i was about to use to make you this utility) no longer supports exporting to gif (it did before)

as far as using png vs gif, i would NOT say to always use png, i bet at many circumstances they can get bigger than gifs and of course the whole ms ie problem

one way to go around the internet explorer png problem is to make flash render your png instead, flash mx and maybe some older versions support publishing background-less swf's. one can put a png in a flash file and save a background-less swf and put that on your page instead. this is of course a lot more cpu intensive as it should be and would probably be silly to add many png to your web page this way, but 1 or 2 may be ok (a lot of advertising people do it like this; when you see those silly things popping up over your webpage and are really slow and weird: thats flash)

to see what i mean check out http://users.wpi.edu/~piotrm/first/flash_png/index.html

Re: Making .gif backgrounds transparent
 

PNGs can actually be made to render transparency correctly in IE5.5+ - see the link below for details:

http://webfx.eae.net/dhtml/pngbehavior/pngbehavior.html

(note: it is somewhat of a workaround, but if it works, it works - I would still like to see fully support by IE in the first place)

Re: Making .gif backgrounds transparent
 

Gifs are totally capable of being transparent. If you have PS7 You can easily accomplish this. I recommend this program stongly, if you are currently using it i will be glad to tell you how to do it.