I'd like to hear more on this to. I listened to a very experienced REALTOR in my area speak to a group and he insisted that presenting his buyer offers to the seller made a HUGE difference in his career and that we should all do the same. The standard is to fax, but he said that's only for lazy agents . . . makes sense to me.
Not sure about your state, but he clued us into the fact that in CA, the DRE allows the buyer agent to present his offer in person to the seller. The listing agent cannot deny you the opportunity to speak to their client (with the listing agent present, of course).