This shirt is awesome, all my lab teachers laugh at it when I wear it to class.  The shirt is very comfortable and it didn't shrink at all.  Also it came in the mail quite fast.

I was suprized by the comments that this shirt is a stolen idea, but I don't think this is true.  This shirt can be found from different stores not produce by this same company.  I did go to the website XKCD that was mentioned in all the bad reviews and I'm sorry to say, but this shirt idea can also be found on cafepress.com. Not sure if XKCD is affiliated with cafepress, but you can also buy this shirt there and more variations of other shirts that are from XKCD.  Furthermore, cafepress has quite a few variations of this same shirt.  I will add though, the one I bought from amazon was a pretty great product. I would buy from this company again.