when to add gelatin?

I was thiking about adding this to help clear up my lager but am a bit confused as to when I should add it. Presumably the act of clearing the beer is also clearing the yeasties and therefore if I do it before bottling there won't be anything left for carbonation???

Thanks

Adding gelatin shouldn't clear out the yeast. From what I've heard, you add gelatin shortly before bottling.

I've used gelatin successfully a few times...
I usually add it 3-4 days before bottling. You want the beer to be pretty much at its final gravity, but give it at least 3 days for the gelatin to settle out.
Here's my procedure
Stir 2 tsp of unflavored gelatin into a cup of cool water, let it soak for 30 min.
Heat to 180 Deg.
Let it cool a little and gently stir in or rack beer onto.

I had the same thoughts about carbonation my first time but have never noticed a diff. in carb. between those with and without

I do it 5 hours before bottling, works fine for me. There will be a lot of different answers on this one though. You may have a different method which suits your personal timetable better.

My timetable is to add whirfloc at the 15 min mark of the boil along with IC. Works like a charm and I don't have to calculate another addition during later phases. Less for me to screw up.

will it work post-carbonation - say in a keg?

It will, but if it's in the keg you really don't need to. Constant cold crashing will clear the beer out a lot.