I first saw the 501st at an event about 2 years ago. Being a huge fan from the class of '77, it was incredibly surreal to suddenly see the troopers and Vader wandering around a theme park. Right there I decided I wanted "in". Its been a long trip via the Rebel Legion and Jedi costumes, but after seeing and working with the troopers at an event for one of our national Deaf and Blind centers, I thought to hell with the comfort factor, I'm going to do it. Yesterday was my first troop, and it was worth the wait.
In the UK Garrison we do the normal sci-fi convention type events, as well as working with charities, childrens hospitals and other institutions. Its events like this that really make it worthwhile. On the 14th December I'll be trooping at the Great Ormond Street Children's hospital Christmas Party in London, and I can't wait.