There is a useful feature for sharepoint. This cross-site lookup add-ons solves a problem that search information in different sites within one site collection. Its main function can be described in three points:

1)lookup information of columns on different sites in one site collection;

2) Convert to SharePoint default Lookup column;

3) Shortcut to the value you want with a keystroke

For more information, you can visit http://www.sharepointboost.com.

Find under: sharepoint cross-site lookup; cross-site lookup; lookup; sharepoint add-ons; sharepoint plug-ins; sharepoint solutions; sharepoint software