On a few of my sites I have several RSS feeds from yahoo news and other RSS feeds, is it a good idea to put the rel="nofollow" in the links of these feeds to keep google and other bots from following the links, thus keeping the PR passing within my own site and not out to these random links?
IMO, since you put effort into placing the links on your site. You should not use the nofollow attribute. The nofollow was designed to allow Webmasters to specify which links do not deserve the link pop. They recommend you use it if you have a guestbook, comment access to blogs, trackbacks and so on - all areas where you can not control the level of links outbound.
But with RSS, you are asking the publishers for the content. The least you can do is link back with some link pop.