A tool for semi-automatic merging of contacts?
One thing you can do is open the Contacts application then press menu and go to "Import/Export". From there, you import from SIM card and import them to your google account. Once you have imported all the contacts, open the google contacts manager and click on "More", then select "Find &amp; Merge Duplicates". 



You may have to go through and edit some manually if they have really different names. But then you can merge again if needed.