Stockholm

[PCruzer]

Will be docked at Frihamnen.  Is the Old Town walkable from there?  If not, what is easiest transport?  Are taxis or Uber easily accessed?

[dfilpus]

No, it is not walkable. Taxi would be fastest. There is the 76 bus, which would take about a half hour to get to Gamla Stan, There is also the harbor ferry 80, which has a dock right at the end of the cruise pier, which takes an hour to get to Gamla Stan. It is a nice scenic route, which includes a change of ferry to ferry 82 at Museum island where you could visit Vasa Museum or Tivoli.

[Apel]

Of course it's walkable. And it is a very nice walk through some lovely parts of Stockholm. But, it will take around an hour on foot and that might not be how you plan to spend your time. Bus 76 is a good option. Takes you from Frihamnen to Gamla stan in 16 minutes (maybe 18-20 minutes if traffic is bad), you can pay for the bus by tapping a Visa or Mastercard in the bus, or use SL's app. 

 

The ferry is also an option as mentioned. A bit slower, but gives you great views of the city from the water. Taxis exist and are usually easy to find, but a small warning: Only use Taxi Stockholm, Taxi Kurir or Sverigetaxi! Avoid other companies, many smaller companies are perfectly fine but there are unfortunately a couple that specialize in scamming tourists.