Narrative:

In level flight, VMC, 10000' MSL, I had a red aircraft, possible an acrobatic small aircraft, just miss my aircraft. ZNY was controling and had pointed out numerous VFR and 1 IFR target. This aircraft was not seen by center nor myself until right on me. I think that all aircraft operating in the us should have a transponder and altitude squawk capability. There was no way I could see this aircraft until it was too close to avoid. ZNY never did get a radar fix on the suspect aircraft, so it was not tracked to landing.

Google
 

Original NASA ASRS Text

Title: MLG HAS NMAC WITH SMA ACROBATIC ACFT. CENTER HAD NO TARGET.

Narrative: IN LEVEL FLT, VMC, 10000' MSL, I HAD A RED ACFT, POSSIBLE AN ACROBATIC SMA, JUST MISS MY ACFT. ZNY WAS CTLING AND HAD POINTED OUT NUMEROUS VFR AND 1 IFR TARGET. THIS ACFT WAS NOT SEEN BY CENTER NOR MYSELF UNTIL RIGHT ON ME. I THINK THAT ALL ACFT OPERATING IN THE U.S. SHOULD HAVE A XPONDER AND ALT SQUAWK CAPABILITY. THERE WAS NO WAY I COULD SEE THIS ACFT UNTIL IT WAS TOO CLOSE TO AVOID. ZNY NEVER DID GET A RADAR FIX ON THE SUSPECT ACFT, SO IT WAS NOT TRACKED TO LNDG.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.