I'm not sure why your cron job needs to revisit the page every hour. From what i understand, this can be done on an on-demand basis, with a cache.
On my site http://www.digitalvibe.co.uk, I have a news section which caches the rss feeds for an hour from when they're requested, and if other people request the same feed in that hour, it pulls it from the cache. If the cached version is over an hour old, the script will download the latest version from the server.
This saves the extra hourly load on the server and removes any unnecessary work - if your site isn't viewed for a few hours, the server is still performing the work via cron, where as with the alternative option, it's only being downloaded when people want to view it and if the cached version has expired.
I use a php script called "magpierss", which handles all of what i've said automatically with a little bit of configuration.
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