ATC Saved My Life Today

When I was returning from my flight today (see previous post) I got flight following from KIND about 20 miles north of the field. 
I was traveling at 3500' in a southeasterly path.
When I got to about 15 miles north, ATC gave me an advisory that there was another aircraft at my 11 o'clock at 3300'.  The controller said if I didn't have them in sight to immediately climb to 4000'.  I climbed without hesitation.  Then I saw the airplane.  From my 10 o'clock coming straight toward my previous location and circling underneath me.  The plane was an expiermental with a wing at the back of the plane and a canard up front.  There was very little chance that this person had seen me.  They were clearly maneuvering.  If I hadn't been instructed to climb, this plane would have been within 100 feet of me, if not closer.
Thank you IND ATC.
For all of you out there who don't file flight plans and don't use flight following, ask yourself...is not having to talk to someone worth your life?