The graph that is drawn for each account is one of the best things about 22seven. What about having this as a more interactive feature? Being able to zoom in, isolate certain time zones, a date and value at any given point on the graph by hovering the mouse pointer over it. That sort of thing. The graphs that are given on xe.com are a good reference. Also, if you could overlay other accounts on the graph so you can see what your current account looked like over your credit etc.
Just a thought. Thanks for the great resource.