Win XP Pro – multiple logons – laptop

I have a Toshiba Laptop (just purchased) and wish to logon to My home domain, plus 2 client networks (both are workgroups).

At present I have to logon to which ever user name i need at the time – go to network settings – alter either to a domain name or to a workgroup name – then restart my laptop.

This is of course a pain as when I logon to my clients network workgroup I have to waist valuable time loggin on twice.

I also found if I accidently tried to logon to a Domain and I am not connected to that Domain I loose everything until I plug in next time.

I have used Password Authentication also but this I have just found is dangerous. Especially when using the OFFLINE FOLDER.

Thanks for the help.