Wouldn’t it be easier to create an email alias that went to the folks who could help with a site? i.e. sphelpdesk@....

Is there something that would require a different group of people  for each site?

We created a contacts list  on our top level portal web  that lists all of the administrators  of the team webs and created views of that list for each of the teams. Then on each team web home page we put a link to the appropriate view of the portal contacts list.

Another option is to create a central help desk site  and link to that site from all others so you can centralize your support and contact  information.

On the same note, something our organization has done that has worked quite well is to create a domain group (example: SharePoint Admins) and add that domain group as admin to all sites, then as people  come and go within our group, all we have to do is update the SharePoint Admins domain group instead of every SharePoint site.

Centralizing support and not attaching a person’s name works well as the environment grows and expands.

I think having a contacts list  and managing it manually may well turn out to be the most manageable option. Our ethos for Sharepoint is definitely distributed management of sites so the Helpdesk will always direct queries to the site  admin first.