I learned about it last year at school when a friend showed me in free-time. Then everyone in my grade got hooked (me being the most proficient obviously ;), and then my friend Tristan Rhee {user:tristanrhee} showed me the new one this year (school year.) I remeber the old front page with a bunker and mario I think. Now aday's it's usually crap that n00bs vote up. :P
I found TPT on DCEMU as a PSP port... I googled it, found unaligned, played for a bit, it died, search again a few month later to see if I could salvage an exe from somewhere and found this :D
I still have the PSP port somewhere.... no idea where though.
My friends had showed me the first powder toy from geeks3d.com. We got into that for a while then got bored. Then one day I found out that a 44.7 existed! This just blew my mind. Strait from powder toy 1.0 to 44.7.
I was on wikipedia on falling sand game page and in other I seen powder toy then I googled it and found the geeks 3d page downloaded it then on youtube I noticed someone mentioning a new powder toy {might have been Andrewrox) got the harwired website from wiki answers and have been with you ever since but only recently in the last few months have I created an account.
At my school in grade 8 this kid I know showed me it and I took a version on my USB stick(it was an ancient version, I think it may have been either 20 or a bit below). I was quite addicted! I played it a fair bit but soon wanted to create an account. I think I actually did on powder.unaligned.org, I forget what happened but I believe at one point I couldn't log in and went searching. I didn't find anything for a while, but after a month or so I found the new website(v30 something). As you can imagine, I downloaded it, played around a bit, and soon made an account. It was really the fact that I wanted to get instructions on how to use devest8a's processor that brought me to the forums. And here I am, with the latest version, frequenting the IRC(freenode.net, #powder) and forums.