Useful Links:
The [http://www.omnigroup.com/mailman/listinfo/omnigraffle-users OmniGraffle-Users] mailing list at OmniGroup.
[http://www.visualdistortion.org/dbgraffle/ DBGraffle] and [http://www.visualdistortion.org/Graffle2SQL/ Graffle2SQL] convert SQL schema to and from /OmniGraffle drawings.