I signed up for a Flickr account, luckily my Yahoo login worked. That helps alot.
Uploading a photo was very simple. The simple photo editing tool could be fun and useful for photos that aren't too over or under lighted.
I can see these uses:
People who can't afford photo editing software who want to make small adjustments and corrections can use this.
This can be an alternative to email sharing of photos and the attendant problems that people have opening them on library PCs or their own PCs at home. They can have their friends create Flickr accounts and print them easily.
If you are sharing photos from a conference and you don't have email addresses or other contact information for everyone who might be interested, you can direct them to the Flickr photos.
Here's a stretch--you put great photos of yourself and your festive life out there, become wildly popular and famous, and the rest is covered by People Weekly.