Into reefs since 1994 (wow - 13 years!), when I was at Georgia Tech. I still have a picture of my 56g around here somewhere, although not very impressive by today's standards.
Current tank setup in spring of 05, so 2 years old.
My current livestock has been in continuous operation for 5 years. The tank has gone from 75g to 15g to 25g and now 40g, but much of it is the same livestock and the rock is the same.
I have been reading salt books for about five or so years and have kept freshwater on/off since I was 8 or so. The tank I have now is less than a year old.