Here's what I did to try and join the RPGA. Go to the link dar posted (http://www.wizards.com/default.asp?x=dc ... ardrequest) and click on the "please contact our Customer Service Department." link at the bottom.
In the search option, type "join" and the 2nd link will be how to join the RPGA (the first is for the DCI). Below is the information from that link. You will need to click on the "email us" tab and submit some information to WOTC.
In order to become a member of the RPGA you must attend an RPGA sanctioned event and obtain a membership card from the event organizer (Senior GM). You can find events in your area using our online Tournament Locator.
If you are unable to attend an event, you may get an RPGA number by sending the following information to Customer Service via the 'E mail Us' tab here.
First Name
Last Name
Mailing Address
City
State/Province
Zip/Postal Code
Country
Phone Number
Birth Date
E-mail Address
I just submitted my stuff to them this morning.
Thats pretty much how it works. Head over to your FLGS and ask for an RPGA card or a DCI card. As noted above, it's the same thing. I went to an LFR event, grabbed a card and signed up really quickly. I also took the DM test and passed so now I can schedule my own events if I so chose.
But you basically need to pick up a card from a store or at an event in order to join. I can "kinda" understand why. You need to go out into the community to join. This action steps gets you out and about, so it's not just you sitting home along anti-social and joining, and then never getting out to the other RPGA members in the area.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.