Self massaging techniques (using foam rollers, "the stick", lacrosse balls, tennis balls, golf balls, pvc pipe, medicine balls, etc) are extremely effective at improving the quality and health of your soft tissue. Many of use have poor length-tension relationships, knots and adhesions, and just general dysfuncion: some of our muscle structures are over active, while others are inhibited. Poor soft tissue quality not only effects how we feel, but also how we perform.
A lot of muscular dysfunction and soft tissue problems arise from the chronic and repetitive movements we perform in our daily lives: sitting at a desk all day, using one arm to "mouse", carrying your brief case or purse on the same side, wearing high heels, rounding the shoulders while keyboarding, etc.
Eric Cressey, a MA based performance enhancement specialist and owner of Cressey Performance, has put together a great little video clip on the series of soft tissue health drills he uses with his clients, and, I'm telling you from experience, this stuff makes a world of difference in how you feel:
You can pick up all of your self massage and soft tissue toolsHERE.