You mean something like this?
$si = Get-View ServiceInstance -Server $global:DefaultVIServer
$sessMgr = Get-View -Id $si.Content.SessionManager -Server $global:DefaultVIServer
$sessMgr.SessionList |
Select UserName,LoginTime,LastActiveTime,IpAddress,UserAgent
Blog: lucd.info Twitter: @LucD22 Co-author PowerCLI Reference