I just saw a neat little RIA over on the Air New Zealand site called How far can I go?. It looks like it was built for travelers who have a specific budget and want to know how far their money will get them. The first pick the originating city and then use a slider on the right side to adjust the amount of money they have to spend. As they move the slider the map in the center zooms in and out showing routes they can afford. If you're flying out of Wellington and you've got $2230 to blow, you can come to San Francisco but if you've just got $65 to spend your choices are a bit more limited.
The interface is simple but well designed. There are hot buttons in the lower right hand corner of the map that allow you to zoom in on a particular region and then see all of the flight prices for that area. On the left hand side of the UI, you have a list of all the tickets you can buy and their prices, so you can scroll through the list and then purchase tickets when you're ready.
I love stuff like this because I think it's a good example of how a well designed RIA can give users more information while making it easier for them to complete a purchase. This gives users control over what they're willing to spend and shows them options in a fun way.
[Via Blog In Black]