Use this tool to find your Flickr user or group ID. Just enter the address of your photostream or group pool and it'll find the number for you. Ways to use your ID: Bananr, Embedded Flash Slideshows, Flickr Leech, flickrRSS plugin for WordPress, Travelr
1001 is a desktop client to be used in conjunction with Flickr, 1001 not only uploads photos to your Flickr account, it notifies you anytime new photos from contacts, tags, anyone, everyone are uploaded.