If you just want to save a question so that you can come back to it later then you can subscribe to it - not to be informed of any further postings but simply to add it to the subscribed list in your user profile i.e. using that list for creating a quick reference to a set of questions that you're interested in, and unsubscribe as soon as you've finished with it.
Thank you Chuck I can see now how it comes up in the address bar, but if I want to go back to find a particular question ( like the one I quoted for example) then where do I find the number. Sorry if I appear a bit thick on this but when people refer to a question where do they get the number from.
First I find the question. I do this either via a search based on name of poster/content, or by remmebering roughly where I saw it, or by looking through the list of questions I answered. My search takes no account of the question number.
When Ii find the question, if I decide to include a link to it in a new posting I simply highlight the address/URL in my address window and copy&paste it into my post. This brings in the question number.
Also if you click on your profile link above the topics there a selection of tabs you can click on where you can see all the questions you've recently looked at or answered.