[support] Extra sitewide variables/configuration - where best to put them?

[J-P Stacey]

Hi,

We're building a site for a client that's taking donations on a rolling 
basis. We'd therefore like to have e.g. the running total of donations 
stored in some centralized place that the client can update, and I was 
wondering where would be the right place to put that.

Any ideas? Extra input fields on admin/settings/site-information would feel 
right, but I'm not sure how to hook into that or if so how to get at the 
additional content from within PHPTemplate.

Best regards,
J-P