you can sign up for a twitter account and block your homepage and block people from following you, to receive twits about bike rides from me:
1. once you have an account, go to settings and hook your cell up
2. then go to your HOME page and click on Following, you should see a list of those your are following and you should see under each name
TURN device ON OFF
(now my twin sister does not see this option on her page, so she clicks on a person she is following and turns the device on on the individual's page)
Twitter is really quite valuable for bike rides, I can instantly twitter the bike riders if there is a problem with a ride or if something last minute happens
which i could not do with email or text messages
I do think this is a good use of Twitter, I will not Twitter you all day long about everything I do, i only twitter in regards to bike rides.