http://forums.tf2maps.net/downloads.php?do=file&id=712 those are track pieces i made for TF2, years ago. they're really minor things, i just had a need for them, and thought others would like them too... well.. they're the 2nd most downloaded model on that site, and have made their way into a lot of user-made TF2 maps.
now, apparently, they are making their way into TF2, by way of one of those maps.
... and valve is paying me for them.
this means that after something like 17 years of trying.... i am about to be a professional video game developer.