Hi Hadley, nice work on this package.
I'd like to suggest an extension to fct_relevel() - an after= argument (a single level specified as a character string or default NA) which specifies a level after which the other levels are to be placed, in the specified order. This would be much more flexible than only moving levels only to the beginning of the level set.
I have a movebefore function for re-ordering data frame columns which is surprisingly useful - often the desired ordering can be obtained with minimal typing with this function. (I use 'before' rather than 'after', but 'after' might fit in better with the current behaviour of fct_relevel()...).
Cheers,
Alec