Auto-repeat Tags

Sorry if this is an obvious point but I have being searching long and for a solution and have to find one.

In my blog I am writing lots of articles that all have the same tags, or vary slightly by one or two. I am looking for a plugin that will autofill the last used tags so that I can either add or delete them as normal but something that will save me a lot of time typing the same tags in repeatedly.

If anybody knows of a way to do this then I would greatly appreciate it!

Thanks