There are some cases where Boxee is displaying incorrect information for a movie where it is just as easy to manually create an NFO file to fix this than to use a tool. I've successfully used manual NFO files like this for a few of my movies, where it doesn't necessarily warrant using one of the NFO tools.
Fortunately, providing you include the IMDB id of the movie in the [i]id[/b] element of the NFO file you only need to include the items which need to be corrected.
Here are a couple of examples of incorrect data which can corrected in this way:
Incorrect or alternative title
Sometimes Boxee may list the movie with a different title than that by which you know it by. For example, I am in the UK and have some movies which were released here with one title and in the US with a different title (such as the 1955 film "The Quatermass Xperiment" which was also known as "The Creeping Unknown" in the US).
An NFO file to fix this just needs:
<title>Your Preferred Title</title>
Incorrect or missing runtime
Sometimes Boxee is missing the runtime of a movie, or lists a runtime which is different from the version of the movie you have. For example, I have the extended DVD versions of The Lord of the Rings movies. Boxee was showing these with the runtime as that of the original theatrical releases.
To fix this just needs:
<runtime>actual runtime in minutes</runtime>
Note: The Boxee NFO documentation shows the value for runtime in the format "nnmin" (where nn is the runtime in minutes) but the "min" part appears to be optional (some NFO generators include it and some don't) and Boxee seems to support it with or without.
These are just a couple of examples, but there are others which can be done in the same way (e.g. release year, rating, etc.).