I am writing a web-app that uses a tagging system to organize the user's submitted reports. Part of it uses ajax to get suggestions for tags to present to the user based on the content of their report. I am looking for suggestions on how to present this information for the user.

I'm not quite certain what a friendly way to do this would be.

Edit:

Well, most of the responses here seem to be focused on the user typing in keywords. The idea I'm trying to define here is more towards presenting the user a set of suggested keywords that they may accept or decline without having to type a tag in manually. (That option is of course still available to them)

---------------------------    # say they can checkoff or select tags they like.
| o[tag2]  x[foo]  o[moo] |
|   x[tag1]   o[bar]      |
---------------------------