Businesses are hard to build and even harder to grow (just ask any successful entrepreneur), but they're easier to create than you might think. This is especially true if you have technical chops, access to a room full of investors, and a lot of caffeine.

I recently had the opportunity to be part of two hackathons--I was a judge for the Mobile App Olympics, a global mobile app competition, and the host of AngelHack, a bicoastal hackathon competition. Teams had one weekend to create a viable product that they had to present in front of a panel of investors, including Blue Run Ventures' Jeff Tannenbaum, Angelpad's Thomas Korte, and 500 Startups founder Dave McClure.

In some cases, developers had thought about their ideas for months. In other cases, ideas and even teams were created on-the-spot. But the end result--the actual products they built in just 48 hours--blew me away. Some products were so complete that they actually resulted in angel investments.

Here were some of the products developed in 48 hours:

PlayPitch, an iPad app that helps you learn songs through interactive sheet music.

Snapstore.me, a simple way to set up an online store through your Craigslist postings. The team even wrote a detailed post describing how they built the product.

Tabber, a program that helps you learn guitar through smart LED lights on the instrument. I've embedded a video demo of Tabber in this post.

Most of the 30-plus product demos I saw at these two hackathons will never see the light of day again. However, a few of these projects have the very real potential to become venture-backed companies. They will be in good company--GroupMe (acquired by Skype) and Zaarly, for example, were created at hackathons. These companies took the seed of an idea, proved that their team could build it, and impressed investors in the process. All of them were created in just 48 hours.

Creating a business isn't the same as growing it, though. There are lots of good ideas, but only a few turn into million-dollar businesses. In the end, it depends on the drive of its creators to turn those products into something more. It's always interesting to see what people can create when they have a problem they want to solve and a few hours to solve it.