I am currently using Aabel from Gigwiz (www.gigawiz.com) which is working exactly as you described and is a really optimized and polished application. The price is also hard to match. I am surprised that it is not more popular. I think that the target audience are mainly scientists, but the plots look really impressive, it builds on a real-time multidimensional structure and even features a database metaphor. It is Mac-only.