Multiple Domains on a XP Pro desktop

I spotted this thread and realise it is old but I am trying anyhow. I have trusts setup on my domain, but I am a techie and it would be useful to have a seperate screen popup before the windows login screen asking which domain I want to login to - and remember old domains I have used in the past. Of course this would have to drop the pc from its current domain and add it to the new one - but this process could be automated from this program I am proposing. Does anyone know of a program such as this? I have looked at making one at it may be a little complicated.