I am yet to find a straight-forward hassle free way to share my Google Reader news on my Twitter. There are many ways to do it on a desktop (Twitterfeed, "Send to" option), but none I could find is a one-click yet customizable option. With ReaderScope beta3 I am trying to solve that problem at least for the Android phone.
You like the news and want to tweet about it? Press Menu, Press the "t" icon. (If you are not logged in, you will be asked to do so first time). You will get a box to type your twit, while the URL is getting shortened in background. After the short URL is ready, insert it (with/without news title). Edit the twit if you want to and hit Post.
Now about the problem mentioned in Market comments:
There was a bug in beta1 that manifested itself in terms of empty lists. If the user presses "Refresh" on first screen and tries to visit a feed he/she has tried to read before hitting refresh; then they will end up with an empty list - with only the title on the top and an unread count. This problem was fixed in beta2. But if you upgraded from beta1 to beta2, the old database stayed unchanged and you will again see the problem. Therefore, if you tried beta1 and are now trying beta2/3, just make sure you uninstall beta1 first.
If you still find any problem in this or other area, please post here on the blog OR tweet me (@jyro). If you post on the Android Market, I will be able to read it (via cyrket), but I haven't found a way to post my comments to the Market. I believe the only way is through the Android Market app on phone (which I don't have at this point). I have managed to communicate through the Package description a bit, but it's a very crude work around with 325 char limit. So try to post here.
Enjoy the beta3!