Just to pass on another technique from Scot Kelby's new book (I don't remember if Katrin covered this) for darkening eyelashes:
Select the areas of eyelashes plus a little with the lasso.
Ctrl-J to copy this onto another layer.
Set upper layer's mode to "multiply"
Add a layer mask and fill with black.
Paint white on the layer mask over the eyelashes.
The last step works best if you have a tablet and use an opacity of around 20% or so.
This technique gives lashes better than reality, so it helps to fade the layer back some afterwards.