Second row O'Driscoll has been named in the Barbarians squad for their three-match summer tour which includes a match against Ireland in Gloucester.
The Ireland-capped trio, who between them have amassed over 500 Munster caps, each received a gift to mark their time with Munster.
Hooker Flannery received his gift from skipper Paul O'Connell, O'Driscoll from Marcus Horan while Ronan O'Gara, the province's long-time out-half and record points scorer, did the honours for Wallace.
Head coach Tony McGahan took his leave - he departs for his native Australia on Wednesday - and Lifeimi Mafi (Perpignan), Tomas O'Leary (London Irish) and Denis Fogarty (Aurillac) also said their goodbyes to the wider group.
The proceedings were supervised by Munster team manager Shaun Payne who also departs in the coming weeks. He returns to his native South Africa where he expects to be involved in non-rugby business activity.
In addition, backs coach Jason Holland and strength & conditioning coach Joey Gallanagh have ended their terms with Munster.
Holland brings to an end an illustrious career that began as a player back in 1999 and ended 102 caps later, after a short break back home, in a management role.
Those players not involved in Ireland's upcoming summer tour to New Zealand will now take a well-earned rest.
Munster's pre-season training regime for the 2012/13 campaign is scheduled to begin on June 19 for some of the players, and June 25 for those involved in the tour of New Zealand.