Sometimes, even after preparing your presentation as well as you can with a presentation software such as Microsoft PowerPoint, you end up in a situation where you are unable to present your efforts because of file formatting problems.
If you find yourself in such situation, you should (A) create PDF/XPS document as a backup, so you can still show your presentation in its most basic form.
One of the founders of Foursquare is Dennis Crowley. The other is Naveen Selvadurai. I know you didn't ask for both but I wanted to give them to you just in case. I hope this helps! (:
