ASP.NET & Integrated Security setup?

[Dave]

Hi,

I've read quite a few places where it recommends you use
integrated security in your connection string.

I tried this in test page to connect to the Northwind
database by setting my connection string to:

"data source=<mymachinename>;initial
catalog=Northwind;integrated security=SSPI;"

It worked as long as I added ASPNET, the account used for
running ASP.NET Worker processes, as a SQL Server Login
with access to Northwind.

My question is should each web application on the server
have it's own ASPNET-type account so it only has accesses
the databases it needs?

For example:
ASPNET_Northwind (This account can only access the
Northwind site and the Northwind database)

ASPNET_Pubs ((This account can only access the Pubs site
and the Pubs database)

etc. If so, how do I do this?

Thanks, Dave.