how do you erase subtitles using photshop?

When I'm trying to get rid of unwanted text on pictures with Photoshop, I usually use the Healing Brush and Clone Stamp tools. (You can see what they look like here: http://simplephotoshop.com/photoshop_tools/indexf.... The key is to select a piece of the picture that is similar to the part you're removing text from, and copy it over, using a very small brush if necessary.

This tutorial is about how to remove the date from a photo, but the advice should be pretty relevant to your query:

http://graphicssoft.about.com/od/digitalphotograph...