Last year i tried to remember to send almost everyone i knew facebook messages on their birthdays.  i wasn't perfect, but in an effort to help my chances, I generally used the pattern:

HB (*insert persons initials), HB!  L, MZ  (*thats my initials!)

simple, thoughtful and a little different. 

Recently, I have gone in a different direction.  I'd call it "bizarro heartfelt."  A sampling (ps. yom kuledet sameach is happy birthday in hebrew.  pps. names have been changed to protect the innocent):

Jody Goldstein:Birthday girl::Mattitiyahu:not wearing pants
both are happening right now. love. mz

yom kuledet sameach. et al. dot com. etc. etc. HB!

Gaw. Happy Birthday. Birthpy Hapday. Daypy HapBirth. Shuffle Up and Fly. Soar to the celebration of you.

(to a chef friend): yom huledet sameach Maya! shower in red wine, shampoo with a reduction, and condition with something force fed. And that's all before breakfast. Enjoy the b-day week and celebrate yourself with verve.

Gorgeousness is the birthplace of Ithaca, the sunrise, and you. I hope the happy of amazonian endowment sends anaconda sized love downriver to your self. happy birthday.

And then sometimes, my thoughtfulness is greatly outweighed by my assiness.  For your pleasure:

(for a friends' anniversary): Tia and Jonny, sitting in a tree, m-a-r-r-i-e-d. First comes love, then comes marriage, then comes debra and jack in a baby carriage.

Tia's response: Mattitiyahu- thanks for your cute Anniversary wish. You got 1 out of the 2 kids names right- not bad :)

My response: im such a raging ass. in my defense, im on pain killers--and i havent met the little human boy yet. A for effort, D+ on the execution.