Since you are an American, the best chance to get into a top school is:
- go to a school with the fewer Americans, so you add diversity. SDA Bocconi and ESSEC come to mind.
- improve your GMAT.

Take a look at GMAT Tiers - strong schools for your GMAT www.find-mba.com/board/27082

I'd also look at top schools in China, Canada, Korea, maybe the MIT-Lisbon MBA?

So you're basically saying I don't really have a chance at Harvard/Wharton/Stanford? I had not considered going outside the US but that's a possibility, I suppose.

No, I think your only strategies for getting into a top US school are:
- take an MS rather than an MBA
- get a GMAT score that's maybe 30 points over the average, and find a leadership role in an edgy NGO
- get a managerial or entrepreneurial job
- Go abroad to a school that partners in the Yale MAM program or the MIT MSMS program, and then come back to one of those for the second year after the first year abroad.

Top Canadian schools are pretty good. Rotman will like you. Ivey's the Harvard of the North.

Gotcha, thanks boss. What would you say are the chances of me finding good jobs in the US with an MBA from a Canadian school?

[quote]I'm aiming at a top tier business school to do my MBA. However, I have scored 680 on the GMAT. Is there any chance at all for me?

Here's my profile:

American male
BA in an arts field - 2009 at a top-30 US college. 3.7 GPA
5 years of total work experience: 2 years as an administrative assistant and 3 years as a project manager. All in the medical field.
Extracurriculars/etcs: have taught voice and piano to low-income children for 1.5 years. Member of a few clubs in college, participated in student government
Main goals: to transition into a marketing role.[/quote]

You'll need an amazing application letter, but you should try. Good luck!

I plan on doing a great application letter! But I don't think that's really enough to give me an edge...

Agreed. I think that if you had a really great story to tell, like how you came up from poverty to open your own business, your essays will really only get you so far. A stronger GMAT would help more.