tangor - 7:52 am on Jun 16, 2010 (gmt 0)
seo1589, welcome to webmasterworld!
White hat is no tricks, just solid HTML, CSS, JS, SQL
Black hat is serving tricks, traps, dealing from bottom of the deck, taking lessons from politicians and lawyers. Usually means exactly what Mark_A said above: serving one page to search engines and something completely different to users, usually by sniffing out IP ranges or User Agents. What "wealth" one can make black hat is very limited, once the SE's figure it out, site is banned. White hat, on the other hand, gets a fairly decent chance at making long term wealth.