I've created a number of 'Reader' users on my portal, yet when theylogin they have no 'MySite' option available to them.Is this correct and if so, what are the minimum access rights for auser to have a 'MySite'?
They need to have "member" access.There is always the option to create your own group too. I think the option you need for My Site is 'Create Personal Site'
As I understand it, the Site Group 'Reader' by default does not have the rights to "create a personal site". Site Settings > Manage Security and Additional Settings > Manage Site Groups >Select ReaderEdit Site Group PermissionsUnder Rights you'll see the different settings that this site group has access to. If I'm not mistaken "Create Personal Site" is the parameter that enables the use of MySite.
Adding people to the "Member" site group gives them permission to create aMy Site.