Changing the SQL Server service account - any additional considerations? I have inherited a few instances that are running under LocalSystem. I need to change this to a domain account as we are changing our backup strategy to go to a network share and then to tape and I need to be able to assign permissions.

I know that the recommended way to change the service account is to use SQL Server Configuration Manager. However, is there anything else I need to be cognizant of? How can I be sure that directory permissions will suffice for the new service account? Will Configuration Manager assign proper permissions to folders that contain the data/log/binaries, regardless of where they are?
Your best bet before you change the service account would be to manually make sure all the permissions are correct.  This will allow you to also document what changes you make so in the future if you need to move the instance to a new server or set up another instance you will all ready have every thing you need.

This is also my preferred method of doing things since I have a slight mistrust of the built in GUI tools for SQL Server and prefer the command line or Windows folder management GUI for security modifications. (too many "Surprises" in the way SSMS does things"

Once you are ready to change the service account, the Sql Server Configuration Manager is the only way to go.  There are some other changes that the manager makes to the system besides just changing the account every thing runs under.