There is a powerful new way in PowerShell v.2 to create new objects from scratch: You should first get yourself an empty hash table object, then add all the information to the hash table and finally use New-Object with its new -Property parameter to turn the hash table into an object.
$hash.Firstname = "Tobias"
$hash.Lastname = "Weltner"
$hash.Age = 99
$object = New-Object PSObject -Property $hash
Your new object can then be used to consolidate information from different sources, or can serve as input object to cmdlets that accept multiple inputs to ValueByPropertyName.