Did 500px.com just give photographers a simple, but effective publicity boost (and Flickr another kick in the ass)? Unless you’ve spent the last week or so in a cave, you probably know that Flickr has just released a new version of its mobile app. It’s got tons of reviews, mostly positive, unlike its web redesign, which alienated many users. But, as some pointed out, Flickr is catching up with other mobile photography apps and is likely to focus on the web property next. Mea