"The Hubway team has been hard at work deploying stations, and nearly 100 stations (out of 140) are expected to be operational by April 2nd, with most remaining stations to be rolled out in early April. Please note: stations along Boylston Street in Brookline and Boston will not be deployed until after the Boston Marathon."
Participants can sign up online for a Hubway Membership. There are monthly and annual memberships available. There is also an option for a one/two day rental for those who are visiting or just want to have some fun touring the city on the weekend.
Interesting in finding out more? Check out TheHubway.com.