Elements isn't free, but it's far cheaper...maybe it's free for students.
Answer: Photoshop! or a photoshop knockoff. Both should have that ability. Additionally, I know Powerpoint can remove backgrounds too, if you have an up-to-date version of it. I don't know how to do that though I just know it can be done.
OP: "If you suddenly skied off a huge fuckin cliff and you only had time to throw one last trick before you died, what would it be?"
Malcolm: "id probably just flail my self to death"
"If the overall quality of your film depends on what you shot it on, you aren't ready to make a film." - Barry Green