Hi Jeremiah,
I know that these posts have told you not to hitchhike, but I'd like to give you some of the other side.
I'm a college-age student and while I wouldn't hitchhike (I'm too nervous to), one of my good friends did this past summer (2009). She went to Germany for a school trip for 3 weeks and then spend the next 2 months couchsurfing, hitchhiking, and waitressing (illegally) until she nearly ran out of money and needed to come back to school for the fall.
She used www.couchsurfing.org, which I've also joined and looks fairly safe. She would spends up to a week with someone and then at the end of that stay, would go to the train station and pick the next cheapest destination, generally working towards Central Europe. Towards the end, she had to hitchhike a lot more, but she said that was safe too.
Now, she had a really good trip. She enjoyed it a lot, but her friends worried about her a lot too. Just make sure to give someone your contact information (maybe you'll have a cell phone?) so that they can check on you once in a while and that you bring a list of phone numbers and email addresses to ask people for help or money if you need it. Just be aware that you are taking risks and I think you'll have a good trip. Of course, I've never done this, but I do know someone that did recently so it is possible.
Hope you have a wonderful trip!