I've been interested in it for a few years, since first hearing about it, but I could never pony up the cash to buy a dedicated GPS unit - especially since I could easily find directions to whereever I needed to go.
Then I got my Palm Pre in October 09. And found geocaching apps for it shortly thereafter.
And went to the 4th party hosted by Spike.
Whereupon he took first Painne, Bloodspyke, and I out to find one, and then Kneelan and I the next day for a "First to Find."
That was July 4th. It's now August 5th and I found my 19th this morning before work.
I really do enjoy it. Especially with others - I was in Texas for the 23rd to the 1st of August and was able to grab 12 caches (1 Earth, 11 regular) with the folks I was staying with.
Playing "treasure hunt" with billion dollar satellites really does rock :D