You should have the ability to do this in any photo programme. The one I use is 16 years old now. However, let me see if I can make you one. Might not be fabulous, but I'll try.
You can download "Easy Gif Animator" from Download.com or Tucows.com (I think). It allows you to make up to 20 animated gifs for free before requiring you to buy the software. That's what I use and it is easy to make them. As a tip, before you make them, make a folder of the pictures you plan to use and if you can, crop and resize them to match (or match as well as possible in shape and dimensions).
Hey great! I found that my photo program I have will do this... just didnt know how, lol For those that would like one and dont have one, that free site sounds great!
I made one a long time ago and decided to make a new one. Got it made but it won't load....HELP!!!! Nothing appears in the avatar box (on my profile, when I try to change avatar)...