It's always healthy to take frequent breaks while playing through a first-person shooter to indulge in other, distinctly different kinds of shooting. If you purchase a specially-marked copy (or Full Deployment Edition) of SOCOM 4, then you should be all set -- Sony has announced that the game will include a voucher that will net you access to the public beta for Resistance 3.
The bundle's announcement on PlayStation Blog doesn't mention when said beta will kick off, but mentions that the voucher itself includes further details. We'll make sure we'll let you know when we get our hands on one of these golden tickets! At least, we assume that they're golden. If not ... well, then, what's the point?