Just a heads up in regards to some earlier statements in this thread.
Although the 501st Charter does not specifically state that there cannot be more than one Detachment per costume type, that is implied and I have confirmed with Albin and Mark (Capt. of the Guard) that this is indeed how Detachments were intended (one per costume type).
The Capt of the Guard has not confirmed receipt of any application form for the Moisture Farm Patrol. This is probably a moot point now since the MFP is not striving for official Detachment status anyway, but unit application forms are available on 501st.com, under Garrisons > Unit Application Forms.
The smallest recognized units within the 501st Legion are actually Outposts (which only require 1 member). However, an Outpost can only be formed in a region currently unoccupied by any existing Outpost or Garrison (so this would not apply within the USA---all areas are spoken for!).
Any formation of an "official" 501st group using the 501st name must be approved by Legion Command. This is because it is too easy for someone to put 501st on a patch or t-shirt and claim to be something that they are not, especially now that the 501st name is being used in gaming communities (Battlefront 2) and collecting forums (501st action figures, etc.). Having the backing of Legion Command will go a long way in helping to grow and promote a group. Note: At this point, the Legion is not sanctioning any additional units other than Detachments, Squads, Outposts and Garrisons. Groups such as the "Tampa Dirty Boys" or "Kilted Trooper Brigade" are not official 501st units...just groups of friends and they do not use the 501st name in conjunction with their identity or merchandise (if any).
I hope this helps clear up a few misconceptions. Personally, I don't see a problem with the formation of any group as long as it doesn't use the 501st name. By remaining unaffiliated with the Legion, you can set your own guidelines, costuming/event standards and make merchandise to your heart's content.
Feel free to ask me any questions and I will get answers for you from Legion Command. Troop on!