Twitter-icon.com has a great selection of twitter icons and buttons.
Site: cabrilloaq.org (Cabrillo Marine Aquarium | San Pedro, California)
Cabrillo Marine Aquarium: A public aquarium which engages all visitors in education, recreation and research to promote knowledge, appreciation and conservation of the marine life and habitats of Southern California.
Do you have a twitter account? If so it's important
to get as many people as possible to follow you.
Great follow me icon captures attention of the visitors
and brings more followers to your twitter account.
Choose great twitter icon for you website!