Last week I talked about how to use Unsum.com to convert partial RSS feeds into full text feeds. While the Unsum method is very general and customizable, it also takes a little effort to identify the content that you care about (determined by looking at the source HTML of the page). Happily FiveFilters.org has a similar tool that will often work with nothing more than the feed URL.
FiveFilters full text feeds (say that five times fast)
If you want to try things out for yourself, the process for creating a feed is pretty straightforward. Head over to http://fivefilters.org/content-only/, enter the URL for a partial RSS feed that you want to convert and click "Create Feed." You'll then be taken to a new page containing your new feed, the url of which you can paste into your RSS reader. If everything goes well, you're done and can move on to the next feed.
For this example, I used the same partial feed I talked about previously with Unsum.com, and had somewhat mixed results. The feed actually gave me an error message saying that it couldn't import the feed, but then it seemed to work anyway (showing the full text of each post). In addition to this issue, the free version of the service is pretty limited, only giving 3 items at a time and leaving a link at the bottom of each feed item. As such, I'm sticking with Unsum for now, but if you don't feel like parsing out HTML elements yourself, it's hard to get easier than FiveFilters.org offering.
It's also worth pointing out that FiveFilters.org also provides a paid option with more items per feed, as well as an option to host the code yourself, without restrictions (other than those imposed by the AGPL under which it is licensed). If you really want a fully customized solution, this latter option may be the way to go.