We do it in my Methodist church, and in the Baptist church I grew up in. But, I agree with you, it is also a very common thing in Charismatic/Pentecostal churches.
In my area here in Ohio, I can’t think of a church that doesn’t do it....including Catholic.
True, I can't think of a Christian church that DOESN'T do this. Catholics certainly use it, the "laying on of hands" is always used for ordinations and confirmations, for example. As with all other Chrisitans, it's a tradition taken from the apostles themselves when the laying of hands was used to invoke the Holy Spirit on believers. As a praticing Roman Catholic, I'm sure Rick Santorum was also familiar with this tradition and didn't need any explanation what the pastors were doing. Here's examples in the Catholic Church:
I don't see why the mainstream media felt the need to explain this in the article and treat it is as some strange, off-putting experience to the casual viewer. Of course, they also insist that only "evangelicals" have a block of socially conservative and "don't think Mormons are Christian" (as if there aren't any pro-lifers in other religious groups and the rest of us treat Mormons as mainstream Chrisitanity), so go figure. Santorum's very existance doesn't gel with the mainstream media's sterotypes about Christianity, so they've been calling him an "evangelical candidate" for President due to the fact he got a large share of votes from Evagelicals. By that logic, Obama is a "Jewish candidate" for President.
Amen. It's a beautiful and holy practice. Having been prayed over in a number of settings, I can vouch for its spritual power and strengthening results.