There's basically three secrets to a good answer to "Tell me a little bit about yourself." Let's talk about them!
1. Follow your resume
The best advice I ever received about this came to me roundabout in a conversation about good interview responses. When I finally asked my coach how one should respond to this, she told me to follow my resume. Here's how you do that.
Origin - Mention briefly where you come from. If you went to university far from your point of origin, mention.
College - Mention your university program, why you chose it, and when you graduate(d).
How Valuable - Segue into your job search by discussing how well you've been able to apply your education to your work experience. Don't go into too much detail, but one concrete example is worth having just in case of a follow-up.
Relax - You're almost at the end of your resume! Here, talk about the Activities you have listed on your resume, and why you joined them. Marching band, volunteering, or Greek life are all worth name-dropping, as your interviewer's response may surprise you!
Ending - Finish out by not-so-subtly pointing out that your experience and education make you a prime candidate for the position. Don't be too forward here, as you could very well lose the interviewer's sympathy with arrogance. At the same time, lacking confidence at the end of this speech is the single best way to fully undercut yourself.
Seriously, I cannot stress this enough: practice your blasted speech! I know far too many business majors who believe themselves to be above practicing, that they can just do it in the pressure cooker. If you're one of these people, awesome. But, frankly, I'm a very outgoing person myself, and this 30-second structured rundown feels so false as to be nerve-racking. So, I practice, and so should you!
Practice in front of a mirror, practice at your roommate, practice at your dog, practice at your best friend, practice at dinner, practice practice practice! It is absolutely imperative that you be able to deliver this entirely off the cuff, naturally, and without shame or self-consciousness.
That said, if you sound like an automaton delivering this speech, scrap it and write a new one. You need to sound natural and unforced without sounding rote. Find the balance; altering the pitches of your voice will help, but it's a bandaid for an arterial wound. That is, it's a small fix for a larger problem.
3. Eye Contact
Hold the recruiter's gaze for the entirety of your speech. I mean it. This is part of why you need to practice; the wall doesn't have a cornea or iris, but the interviewer does. You need to be able to look them in the eye without flinching, fidgeting, or flailing. Don't look away from them, even to think. If you must catch yourself, compose yourself by closing your eyes and taking a breath, rather than looking away.
But once you have this perfected, this most annoying first question will set the tenor of your entire interview. I can assure you; following the OCHRE format should help you deliver a pitch perfect response. (Your ability to produce puns, however, I cannot speak for.)
For some really good examples of 30-second pitches, check out these videos from the PWC Pitch Contest.