There are quite a few online tools (as well as desktop software, of course) to help Web professionals develop flash presentations, but none are like UK-based Prezi. The solution is an amazingly quick and easy way to develop what Prezi calls "zooming" presentations.
The concept itself is difficult to explain, but imagine instead of boring old PowerPoint slides, you could add some lively movement to the content without having to spend hours customizing separate slides in flash. That's Prezi. You really have to see it in action to understand how it works. Fortunately, there are quite a few presentations created by community users in the showcase area to give you a good idea of how it could work.
Prezi offers a few different plans. The free version (which is sufficient to fully try out the service) includes the Prezi editor, allows users to import creative (images, videos, PDF, and flash files), includes the ability to create groups (to share and collaborate with others) and embed the final presentation into websites. Users are even able to download the presentation they create. The downside is you'll have the Prezi logo on your work. Upgrading solves that minor problem and offers quite a few other noteworthy features.
The Private Prezi solution offers 500 MB of space (compared to just 100 in the free public version) and provides an offline player. A few extra dollars every year will give users an offline editor, and 2GB of space, which is well suited for those in the enterprise. While not a substitute for more sophisticated animation, it is a interesting solution worth a look (especially if you need some storage to host the presentations you create).