Openside flanker O'Hara played his schools rugby with PBC and now plays for UL Bohemians where he studies business.
He impressed for the Ireland Under-20 in last summer's IRB Junior World Championship in Japan, where he was the only Munster player to start all three of Ireland's pool games.
Youghal youngster O'Callaghan played at schools level with Midleton College and now plays his club rugby for UCC at number 6.
He also lined out for the Ireland Under-20s in Japan and made his Munster debut in August, coming on as a replacement against the Sale Sharks in a pre-season friendly at Musgrave Park.
2009/10 MUNSTER RUGBY ACADEMY:
Stephen Archer, Danny Barnes, Andrew Burke, Scott Deasy, Kieran Essex, Dave Foley, Eoghan Grace, Conor Murray, Ian Nagle, Peter O'Mahony, Pa O'Regan, Paul Rowley, Mike Sherry, Dave O'Callaghan, Brian O'Hara.