So, you have a little network with some shares you frequently mount, i.e. you have a „Music“-Share on your home-server. You connect, you drag the newly mounted share to the „Devices“ section, some time later you restart your computer, and when reconnecting to your share the mount does not reappear unter „Devices“. Damn, again dragging the share, and again, and again, and again. Sounds familiar? Here’s how you fix that.
You will want the Property List Editor shipped with Apples X-Code (you should find it seperately too).
Firstly you need to connect to the shares you want to add to the sidebar. Next you go to the „Library/Preferences“ folder in your User directory and find the file ‚com.apple.sidebarlists.plist‘.
/Users/<Username>/Library/Preferences/com.apple.sidebarlists.plist
Open this file with the Property List Editor and navigate to Root->systemitems->VolumeList there you have many entries named „itemX“ where X is a number greater than 1. Now this list can be really long so you have to check every Item if the „Name“ has the value of your Sharename. Most propably the item is missing the „EntryType“, it needs to have the value of 8.
If it doesn’t exist just richt click on your „itemX“ entry and click „Add Row“, change the type to „Number“ and give it the value of 8. You need to repeat this for every share you wan’t to add to the sidebar. Save the changes and restart the system (restarting finder should be sufficient, I haven’t tested this though) and you’ll find that uppon reconnecting the share the entry appears under „Devices“.
Update: Snow Leopard does not seem to require this trick anymore. Everything seems to be working as it should again.