In my freshman year of high school I attended a Catholic school in which students attended Mass every Friday. During the "Liturgy of the Announcements" (to borrow a phrase from LarryD) those who had birthdays during the week would go up in front of the altar and everyone in attendance would extend their right hands toward the birthday kids and recite a blessing led by the officiating priest. I found this disturbing, and not just because it made us look like we were giving the Nazi salute.
The problem with the birthday blessing and other such congregational participation exercises is that they can cause confusion about the different roles of the priest and the laity. However, the Charismatic Catholics who practice such things are not entirely wrong. All Christians belong the priesthood of believers and God can and will bless others through us. As one of my professors put it, the priesthood of believers is higher than the Levitical priesthood because we have the Sacraments. The Levites tended to the tabernacle but we are tabernacles. Through the priesthood of believers, God blesses people and even offers sanctifying grace through marriage and in extraordinary circumstances. A layperson laying their hands on you and praying over you may seem weird or "Protestanty" but there is absolutely nothing wrong with it provided that it is done outside of Mass and does not cause confusion about the special status of ministerial priests. We should defend the ministerial priesthood but we must be careful not to denigrate the priesthood of believers.