You might also "get up to speed" using WebLogic's 4.0 EJB Application Server. You can download it for a 30 day eval from www.beasys.com ... Supposedly, WebLogic holds some 70+% of the EJB market.
Also check out Orion Server. It's free for non-commerical and development use, and only $1500 for commercial use. It's quite fast, and implements the full J2EE spec.