Dlume is nice, gtk2-based addressbook. You can easily add, edit
and delete records to/from database (but Dlume doesn't rely on an outside 
database - It stores your contacts in XML format). The Quick-search 
feature allows you find required entry in comfortable way. Export to
CSV and HTML formats is also available. Interface design was borrowed 
and improved from Paddress (http://paddress.sourceforge.net).