Here is some more about Birkat Kohanim - from today's Hahkel Email. May we merit to be blessed by the Kohanim in the Beit Hamikdash with the coming of Mashiach ASAP!
3. Finally, there is a wonderful lesson learned from the fact that Birkas Kohanim was first recited in the desert--before the Aharon and his sons received Terumos, Bikkurim and the like as the Matanos Kehuna. If they would have already been receiving these gifts, then in blessing the people they would also be blessing themselves--for when the people had more bounty, so would they. This is not the optimum way of giving a bracha--blessing someone else with one's personal interests in mind as well. Rather, the Torah teaches--when giving a bracha give it with a full and selfless heart--focusing exclusively and entirely on what is best for the recipient of the bracha, and not regarding for the moment how you could 'also' benefit from the very same blessing. Be effusive in your bracha--but also make sure to make it pristine, wholesome, untainted and pure!