i used photoshop.. use a blank new document and then start
opening the pics one by one and dragging the layer into the blank
document. then slowly resize and cut and put them all together.
it's great when the seperate pics still stay on their own layers so
i can manipulate them seperately, incl the colour and levels and
all those. but i did minimal editing to the pics, so many to paste,
too little time! ehhehe
yeah main thing about photographing in rain is of course, keeping
the camera dry. 
