CRM callouts - not very straightforward

I've been looking into bridging our CRM 3.0 installation with the billing section of Quickbooks so we can do simple imports and exports of data between the two. So far, as far as I can tell, this might be more work than I initially suspected. Although not directly related to this, I did find a good write up on how the callout functions have evolved from 1.x to 3.x

I like doing little 'quickhack' widgets from time to time that do functions like this, but it looks like this will be more than just a quickhack.

A CRM-centric blog, and the callback info I talked about, can be found here: http://blogs.msdn.com/mikemill/archive/2004/12/09/279021.aspx