I did a regional internship two years ago, and it didn't do me a damn bit of good getting hired even though I got excellent evaluations & the company has continued to hire. I was a victim of circumstance, timing, and personal changes, but my work as an intern (and I busted my ass) hasn't provided me any advantages compared to any other street hire.
Later, did a long-term paid internship at a large international company, and had the best year of my life. I also got some wonderful work experiences & skills outside of flying airplanes. I made decent money, got to flight instruct on the side for extra cash & flight time, and networked like CRAZY. I hope to be back there as soon as possible.
My personal opinion having been there - If you get the opportunity for a paid internship or an internship at a good hiring large company (SWA, Alaska, Continental, UPS, FedEx, Wal-Mart, IBM, Coca-Cola, Cessna, Raytheon, United Technologies, etc), then take it...otherwise, stay out of debt & stay away from an upaid regional internship, and fly your tail off with that time.