Be careful, though. It's easy to talk about how one's software is going to change the old way all the others do it, because they're wrongheaded, et cetera, ad nauseum. I listened to ModernBill's pretty talk at their v5 launch party back in March 2004. They had all these things to say about how the accounting was going to be improved, this was going to work better, that was going to work better...it took them three years to release a product that actually *worked* in a production environment, and it didn't do some of the things they had touted and gotten everyone excited about. And, hey, guess what? Parallels Plesk Billing -=is=- ModernBill. They bought it, rebranded it, cleaned it up, released a new dot-rev...and you can't own the software license. You can only lease.
No way am I drinking any more of that particular Kool-aid...