1. Go to twitchalerts.com
2. Log in by clicking "Launch Twitch Alerts" and connect to the absurdminds twitch account.
Be sure you don't accidentally connect to your own twitch.
3. Choose any steam widget. "Alert Box" seems pretty popular.
4. In OBS, under "Sources", right click and choose "Window capture".
5. Make it look like this:
http://i.imgur.com/efvSb57.png
6. Make sure your Window Capture is above your game capture. You can edit the position by right-clicking the window capture and choosing "order".
7. Click "Preview Stream" and then "Edit Scene".
8. Move the twitch alerts box someplace nice and then resize it so it's not huge.