Vista Lite technically isn't legal. I don't think it's certified by Microsoft. Not exactly sure they would approve of people removing things from Vista.
As for me getting Vista for free, it was through the Power Together initiative from Microsoft. I happened a while ago and the site links to MSDN now.
Basically there were two sides to the site: Vista and Office. You choose the side and you register. Then you can choose from a huge list of webcasts ranging from business to software programming and you must watch three. The site logs when you've finished the webcast, so it'll know when you've watched three. After you're done, you just wait 6 to 8 weeks for it to come a viola! A copy of Windows Vista Business or Office 2007 Professional.