okay, this has been discussed a lot. In fact, there have probably been 2 threads on this exact same topic in the last month alone. That being said, we all know someone will answer anything anyway, so to repeat the repetition of a hundred previous threads...
Yes it can seem like sucking up
Don't do it cause it is silly
Do it because it is what all professionals do in the business world already
No it's not sucking up
You should only send one if the interviewer was particularly helpful
Make sure it isn't generic
Even if it isn't generic it is still cheesy
Make sure you send one as soon as the first week
Remember that you need to send it by the first month
Sending it could actually hurt your application
Sending it could actually help your application
I believe that is the gist of the variety of responses you normally get to this question, minus the anecdotal evidence. So I hope that helps you to make your decision.