Image sorting

[bobberella]

i tend to get a little trigger happy when saving images from the net
for example, i'll visit a few tumblr pages and in a few short weeks i've suddenly collected a few hundred new pictures

what's a fairly easy way to sort a large collection of image files?

right now i'm just dragging and dropping and it's taking a very long time
my external drive claims i have 16,827 files
granted i could delete a good portion of that, there's likely a lot of duplicates and inferior quality files,
but deleting only happens as i find them.

is there a way to maybe highlight several images and then hit a keyboard shortcut that sends them to a predetermined folder…?