Instead of writing your own invoice system, check out Cashboard 
</shameless plug>
Keep up to date with Rails on Twitter and This Week in Rails
Policies: Conduct, License, Maintenance, Security, Trademarks
Instead of writing your own invoice system, check out Cashboard
</shameless plug>
Keep up to date with Rails on Twitter and This Week in Rails
Policies: Conduct, License, Maintenance, Security, Trademarks