To my knowledge we haven't done anything (yet) for 2013, but in 2012 we made custom plaques with out CNC Mill. Then we painted the inside of the letters with blue paint. I remember my first freshman year project was to remove any access paint from outside the letters. Oh the memories
(although I wasn't a freshman, but a sophomore. 1st year student on the team nevertheless)
I'm sure a lot of teams did this but we also honor our sponsors by putting them on our robot and such.
These are what teams get for their assistance to us:
$100-499 = Name on website (and link to their website)
$500-999 = Name on back of shirt (as well as our website, as well as a small description of the business)
$1,000-4,999 = Name on robot (as well as all those listed above)
$5,000+ = Name on trailer (as well as those listed above)
We try to get an email contact from our sponsors and send them updates on how the team is doing. We also encourage that they like our Facebook page. That way they know how we are doing, and our more encouraged to stay with us into the next season.