I can't sing the praises of 1001 enough. Not only does it function extremely well, the interface and usability will be seamless for Mac users.

I'd estimate that 1001 says me at least 60% in the time I spend uploading photos to flickr.

All I can say is that if you use flickr, and you use a Mac, just give this a quick try and see if you can go back to your old ways. A few tips that took me a while to figure out:

1) You can select all (or shift-select some) of your thumbnails and apply everything universally. So with multiple thumbnails selected, you can send to groups and sets, add tags, and even type in a common title or description all in one swoop. Then you can go back and add individual groups or tags for each individual photo if you want.

2) When the groups or tags panes are active, you can just start typing the name or the group or tag and it will bring it right up. If you type a tag name that it doesn't recognize, it automatically creates a new tag for you.

I've never registered a freeware product so quickly in my life. If you want to cut the tedium of uploading to Flickr just give thi a try.

(And I'm not even going to go into the photostream option, which is another great component to 1001.)