Four years ago, there was one big, unavoidable photo-sharing site that pretty much dominated photo sharing. Whenever a party went down, or a concert, or a social event anywhere in America, photos of it were posted to this site. And if you wanted to view those photos, you went to Flickr…

A few short years later, Flickr is teetering on the edge of irrelevance. Thanks to a period of mishandling, the Yahoo-owned photo sharing network is fighting to re-establish itself as a major player in mobile photo sharing. As GigaOm has astutely pointed out, the Flickr app is 104th in the Photo/Video section in iTunes.

Finally, Flickr is striking back with its own tricked out iPhone app, complete with Instagram-ish filters and all. But can Flickr really get all that momentum back?

Flickr hasn’t been as poorly handled as Myspace or anything, but it’s definitely an example of a has-been web giant that is trying to stage a comeback in a very competitive and crowded market. BUT Flickr is doing some very smart things…

On the marketing side

First off, Flickr has taken a page out of the Instagram/Pinterest playbook. They’ve made it easy to share Flickr photos via Facebook and Tumblr (no Twitter?). Not only will all of your friends see your captivating, artistically-filtered photo — they’ll also serve as advertisements for Flickr.

Basically, they’ll announce that Flickr is going to be relevant again, which is the perfect message for a site that needs users to come back to and dust off their old accounts.

On the functional side

The new Flickr app gives users an Instagram-like experience with 16 filters and a photo-discovery feed. Actually, Flickr will give users a lot more photo-editing options, with the ability to zoom and crop with much higher quality resolutions.

Will it work? How long has it been since you logged into your Flickr account? Let me know in the comments section!