This doesn't have anything to do with the business classes I've taken. I've just known for a while that I am interested in entrepreneurial activities, and I thought that having my own company can be useful for a variety of reasons. For instance, recently a classmate asked me to make a prototype for a business idea of his. Having an official business to fund various projects like that is helpful to me. I have lots of other side projects I'd like to explore as possible businesses, and now I have a platform to do that from.
And it sounds a bit silly, but another reason to have an LLC is that the sooner you open a corporation, the longer you can say you have been in business. It's a lot more legitimate to say to potential investors, "I've been around for six years" instead of "I filed the papers yesterday."
Also, some grad students eventually do consulting work. I don't have any consulting job offers or plans to do that at the moment, but if I want to do that in the future, I can invoice and charge my time from the company rather than just sketchily pocketing cash.
I used an online lawfirm to do the paperwork for me, and I've incorporated in Delaware. I'm the sole owner and member. I've opened a business checking account at Bank of America, and I have an official business debit card.
Bring it on!