Stack Reminder allows you to save questions/answers to a special list, each with their own custom flag to remind you why you wanted the reminder in the first place.
This tool is a great resource when you are browsing around Stack Exchange, but cannot contribute until later. This will let you mark anything you would like to come back to later.
Stack Reminder is a free userscript for Tampermonkey. You can download it here for 10 easy payments of $0.00.
Once the script is installed, it will request an API key, which you can generate for free using the "Generate API Key" button above.