small invoice system

I'm looking for a small program to generate
simple invoices for some consulting work I do.

I would like to wean myself from Quicken Small Business
and would prefer something that uses MySql for a backend.

I only want to dump a day or two into setting it up so
want to stay clear of any complications (i'm a Debian user
spoiled by apt :-)

Any tips would be appreciated

v/r
Mike