This rack was designed by a guy who does adventure races (you know, with the compass, and the running and the biking, etc) so that he could store his team's bikes easily at transitions. This would work equally well for triathlons or your garage. If you need to store more bikes, the design is simple enough that you can easily modify for more or fewer bikes.
The thing I like best about this design is that it's easily broken down for storage/transport. The upright supports aren't glued into their bases, so you can remove them and store them in the horizontally-aligned supports.