I am Christian and I definitely believe in Angels and find it to be one of the most amazing things ever. Apart from the bible I believe that it is how we have connection to "the other world" (for lack of a better term).

A movie that shows all that you found in the bible on Angels really well is "City of Angels" with Meg Ryan and Nicholas Cage. Its one of my favourite movies and sums up exactly what I think an Angel is.
Make sure you watch it if you havent seen it.

I have felt some sort of presense as well. It is hard to explain but it is real enough in my mind to know that it is there.

I have heard psychics say to people that they have people watching over them. I think this is different to an Angel as I dont think that humans can become angels when they die (as much as I would love to). I believe we go to heaven and God has another purpose for us there.

This is a really interesting topic Love it!