I want to give a client access to a SQL server instance so they can execute a stored proc, or run a view, but ideally I don't want to give them SQL Server management studio as they are non technical.
Are there any free and easy to use remote admin / reporting utilities for SQL Server?
Not that I am aware of.
It sounds to me like you would be better off creating a simple web form/win form that provides your client with access to only the specific features and processes they require. Doing so would avoid confusing the client with all the unecessary complexity that manage studio would present them with.
I'm no programming guru but putting something basic together like this, say using .NET, could be done in a couple of hours, inluding impementing apporpriate security. I suspect you could probably find all the information you require in order to do this on the ASP.Net tutorials.
MS Access isn't free, but if they already have it then you're set. Just create an Access Data Project (adp) against the database, and only give them execute access on the views/stored procs that you want them to use. It's simple point-and-click for them to run a sproc, and it prompts them for the parameter values.
If you are on SQL Server 2008, Report Builder 2.0 (free download) is a tool designed to allow end users to create reports from a variety of data sources including views and report models.
More information here.
If its a specific stored procedure or its to view a specific view, why not write your own single purpose application? It shouldn't take long at all and then you will control the interface.