Curation, it's all about curation. What is curation? Adding value to information.
Activity - publish, don't just read. Use the Scoop.it bookmarklet (works great on the iPad) to publish interesting items you find, as well as the suggestions on the Scoop.it site itself.
Share - don't just publish. Use the widgets in your sidebar if you want to, but you can add value to your Twitter and Facebook networks by publishing there too.
RSS - use Scoop.it's "RSS everywhere" to keep up to date with what your community is doing on the site, especially topics/followed.
If you like playing games, remember to check out the leaderboard. If you like that sort of thing.
Don't try to reproduce a community you are already a member of on another network, create a unique Scoop.it community composed of the best contributors. Scoop.it make this rather difficult, constantly suggesting your Twitter subscribers to you. However, a useful member of your Twitter community may not add much value to your Scoop.it network, so make then distinctive.
The Big One: Why do I want to do this? Because you want to participate in a community and not just be a leech?
Isn't this just strengthening the echo chamber? Not if you curate - amplify and add value to content, not just save links for your own use.