[Adam Randall]

Yep thats pretty much exactly what we do.

We use a PSA system (professional systems automation) that works on whats called service boards.

It has a marketing manager and an oportunity module.
When we do any work relating to marketing and that includes attending seminars or going to morning breakfasts etc, the time is put against the marketing service board to its appropriate category eg: construction mailout

We still mark the time as billable, however it bills the time automatically to our own company.
We do not pass this amount onto our financial package so that the figures can be reported but do not effect actual real world accounts.

Expenses however (like stamps) are mapped and passed onto the appropriate expense account in quickbooks.

We also setup seperate "oportunity sources" so for instance I have been doing a mail out to the construction industry in Adelaide.
Any business we get from these marketing campaigns are attributed to my "construction mailout" campaign or whatever campaign they are generated from.

This includes any one off purchases and also re-occuring revenue so I can look back in 5 years time and say - OK that particular mail out generated us a total of $25,000 over 5 years.

We have campaigns for:
Employee generated (with sub categories for names)
Website
Toastmasters
East side Business enterprise centre
Rotary
Client referal
Family referal

Others but I cannot remember now

I also should clarify, we treat networking as just a branch of our general marketing strategy, we do not treat it as a seperate entity.