I have used 1 .. It has been mentioned in a older thread . Do a search. I am currently using the site and have been for a long time. I play at pokerstars and the poster earlier on this thread is right about pokerstars having a rule as to not talk about any such transactions.
You go to the trusted website , click on sell chips tab (it will say on the web page if their selling at that time) if it says they are selling chips than you click on the tab button and a chat box will appear and a operator will ask you to sit down at the table and tell you to transfer the play money in to the player that the operator names in the chat box. So you go onto pokerstars look up that table and you transfer your play money into the named player at the table.. Then it takes a few minutes for the real money to be added to your account. The operator will stay on with you via the chat box from the website so you can talk with him while your waiting for the transaction. Google "selling pokerstars play money" if the site looks like pokerstars you probably are at the right site ..Hint Hint
If your scared just tell the operator this is your first time doing this and is it allright to do 1 million at a time just for your safety. they will understand and go ahead with proceeding that way.
Also sign up to the web site they will email you when they are buying play chips..