Kip noted yesterday about WLPG getting an update from Windows Update and included a Microsoft KB link, but what that link doesn't contain was what else might have come with that update. The latest WPLG update support uploading to Flickr, you can now upload your pictures to your Flickr account.
It works the same way as if you upload to your Live Space, so you select the photos you want to upload, click on Publish, then choose Services (if it's the first time doing it) and choose Flickr:
If it's not your first time doing this, then click on Publish and then Publish on Flickr:
You will then need to authorise WLPG to access your Flickr account which will open a browser window for you to log into Flickr, once you have done that, then you can continue:
Which then gives you the following where you can choose further options for uploading:
Then you're good to go
And there you have it, your new set of photos on Flickr.Microsoft, Windows Live, Photo Gallery, Flickr, Windows Live Photo Gallery