This works but it seems like terrible practice - should we detect/deny using $_ as a user defined variable?
(At PSCONF.EU and a customer's colleague is doing this in his code)

foreach ($_ in gps | where {$.name -like "*SS"})
{
$.name
}

This also works:

$_ = "test"
write-host -ForegroundColor red "Thiis is a $_ "