When using MS SQL Server in a non-domain network (peer-to-peer) it becomes difficult, IMO, to use windows authentication, aka Integrated Security=SSPI. The only way I can get it to work is to make sure the same user and password exists on both the server and client. Seems to me that could grow into a support nightmare the larger the user base would get. Besides using SQL authentication instead, is there any other way to use windows authentication like telling the server to trust the other computers?

I think to do this you need domains. You can then set up trusted domains. Without domains you are in workgroup mode. There you probably are best to not use windows authentication but sql authentication.

a) yes, you need domains to make windows authentication as you wish b) even if in workgroup you still want to use win authentication because of security issues