Google are closing Picnik on April 19, 2012 (very soon). If you use Picasa, Photobucket, Facebook or Flickr the chances are you have used and come to love Picnik. Google have in fact used many of the features of picnik in google+ photo creative kit but the users of the other packages might really miss picnic. Flickr has at least indicated they are working on an alternative, but I haven’t noticed an official notification of that yet.
For those looking for an alternative now, have a look at Aviary. It may not be as well integrated as picnik was but it does have a very comprehensive range of photo editing features available as standalone on PCs, web and mobile apps.
If you have photos still in a picnik account you can use the picnik takeout feature to download them to your computer (in a zip file).