Hi,
is it possible to share remote powershell sessions between powershell processes? For example, I open one powershell console and establish a remote session to host foo. Then I open another PS console and I would like to enter the session to foo created on the first console. Can this be done?

No you can't do that, not for remoting sessions or background jobs.

Thanks for the answer.

I am developing a system for managing multiple Exchange 2010 servers in separated domains. I have a single windows computer which acts as an administration host. It hosts a custom Perl script which works as an RPC-like server, from which a PS script is launched which connects to remote Exchange machines through WinRM, does the task and returns results. Problem is this takes a lot of time (approximately 10 seconds for each request), most of which is spent on establishing a session to the remote host (about 7-8 secs). So I thought of keeping a constant pool of open sessions to each remote host and just passing them to the RPC script when needed. Could someone propose a better solution to speed it up, or suggest how to best implement my solution?

Shay is correct that there's no built-in way to accomplish this.

However, I do want to get around to testing this 3rd party (unsupported) add-on in a scenario that you describe:
http://code.msdn.microsoft.com/PowerShellTunnel