I say this once and I've said in 100's of times: Twitter has revolutionized my professional engagement. It has allowed me to experiment with ideas, share thoughts, collaborate, debate, nit pic thoughts, expand ideas and much more.
It has allowed me to distill what I think is important and it has also allowed me to step out of my limited professional circles in this small (albeit nice) private school.
I had a sense that my Twitter birthday was coming up and then found a site that would actually tell me how long I've been twittering.
Much like parenting, I barely remember being without Twitter and might have thought my Twitter time line was longer than it really is.