I've been paying Amazon about $20 per month to host a remote instance of Windows Server running the OPML Editor, which "polls" OPML files on a regular basis to produce Rivers of News (for me and my astrology blog).
Not sure if this is worth the money. I paid a one-time licensing fee of $35 to host Fever on my VPS. It isn't costing me extra to run the software (i.e., the added bandwidth falls within my current hosting plan).
The astrology river garnered less than 1000 pageviews over the past month and yielded one penny in Adsense income.
I mostly look at my tabbed rivers to see what Dave Winer has posted, but I can just as easily add all his feeds to Fever.