10 minutes sounds about right. But if you must have quick changes, go here:
http://www.fastfrankracing.com/
Basically you have to spend a lot of money to do this stuff. Special axles, captive spacers, captive rear calipers, brackets that allow wheel swaps without caliper removal, special spools and corresponding paddock lifts if you want to get race-quick swaps, etc. etc.
The one thing I am going for is captive spacers. A close second (on my bike) would be a captive rear caliper, but I've figured a decent workaround for aligning the bracket that replicates the function of an alignment tool.