I was just fiddling with gReader when I noticed that by default the application saves the feeds to the phone memory. So I immediately changed that to SD card memory. However, on doing this all the existing feeds were lost and I had to do a resync. I have a feeling the app didn't delete the existing feeds from the phone memory. Any idea how I can delete those feeds from Phone memory manually?
From your Home Screen go to Menu -> Settings -> Applications -> Manage Applications and find gReader. Then click the Clear Cache and Clear Data button. This may lead to you having to sign back in but it will synch with your feeds so you won't really lose anything.