Are there any requirements for participating in Area 51? Can Joe Schmoe from the internet come propose or follow a site, or do you have to be a participant in an existing SOFU/SE site?
Rep requirement from the FAQ:
25 Create example questions 50 Create proposals and example questions 50 Vote a question as on-topic or off-topic 50 Flag offensive 50 Leave comments † 150 Vote to delete a question (costs 1 rep) 250 Vote to close or reopen your proposals 1000 Edit other people's posts (proposals and questions) 2000 Vote to close or reopen any proposal 10000 Delete closed questions, access to moderation tools
Note that you get +50 rep for verifying your email on Area 51, and +100 for associating with another network site (as long as you have +200 somewhere in the network).