Im going to be in Glasgow/ Edinburgh and would like to take a railroad equivalent of hop on hop off to Inverness , Does such a thing exist? Not interested in the 9 day trips that include lodging and food. What are the best railroad sightseeing options?
Check out the ScotRail passes. There are a couple of options. We'll be doing the Spirit of Scotland pass which also includes many buses and ferries.
On the same link, follow their "inspiration" tab for more detail on recommended scenic lines.