Problem: I feel sad becuase I have so little money.

Solution: give things away.  Seriously.  Even if you don't have money to spend, I bet you have a lot to give to others.  Give your time (this is especially precious and appreciated in law school, where everyone is busy and frazzled), give someone a hug, give someone a smile, give someone a break, give someone a shoulder rub, give an answer in class, give someone a kleenex, make soup and give some to your neighbor (my neighbor does this and it makes me smile all day)...When you see how much you can give, you'll appreciate the simple abundance and richness of your life. 

I tried this when I was self-employed (a.k.a. broke) and starting my own business.  During the month of my 29th birthday, I gave something away each day (my birthday is in February, so it worked out to 29 days of giving).  By the end of the month, I felt like a million bucks.

This was not an original idea.  I heard about it on NPR.  If you'd like to try this and share with others who are giving things away, you can sign up for the "29 Gifts" project at http://www.29gifts.org/.  Or, read the book (available on Amazon here).  When you are done reading the book you can give it away. :)