Here's v3.0: http://www.filefront.com/14977233/sandpit-v3.0.zip/
There are a few small changes/fixes and some small performance improvements. The main change is that I've updated the source code to compile in Visual Studio 2008.
As I recall it, you just put in the numbers from the front, then some numbers from the back and a few other details and your address etc and that's it.
I think the only requirement is that have a credit card that Steam accepts.
Interesting find.
Have you looked at the Gearbox .plan files on Blue's News? There's some interesting stuff there, like that the Shock Trooper was prototyped with the voice of Greedo from Star Wars: http://www.bluesnews.com/cgi-bin/finger.pl?id=293&time=19991028175005
Yeah I already looked on FilePlanet but couldn't find it. They've got all the other Bink videos and a Half-Life recreation of the techdemo map.
Also, was there more than one version of these E3 videos released? I found a video on my hard drive that had a few snippets of the E3 videos, but Alyx...