In short, the 48 Hr Experiment is a challenge to launch a SaaS product in 48 hours (12 days of 4 hr coding sessions.) The following excerpts will tell you about how it came to be and what SaaS product I decided to build.
Excerpt from my first post on this blog:
While studying for my upcoming chemistry final, I had an idea for an experiment. I want to see if I can create and launch a marketing software (offered as a service) in 48 hours or less. 12 days x 4-hr sessions = 48 hrs. Why 48 hours? To force myself to solve only a small problem with a simple solution. Another reason is because I will be taking summer classes (Biology & Physics) so I don’t have much time. And according to David Heinemeier Hansson, this is a good thing.
Excerpt from my second post:
The problem I have decided to focus on is Bite-Size Chemistry Lesson in my RSS Reader because it’s the one that I will need to use almost daily for the next 3 to 5 years in my quest to becoming a medical doctor. It also has good commercial applications and was also most recommended in the feedback I’ve received on my blog, friends and business mentors.
48-Hour Launch 
I am trying to read through your blog on my new iphone4, but its not functioning for some reason. Can you let me and other viewers know what we have to do to browse it via this kind of device.