Sometimes you need to add an option for public upload of images on your site under certain galleries to increase the interactivity with visitors. If your site is on WordPress, you can use following plugins to achieve the same. Of course there should be a moderation options to avoid some unwanted images to show under the gallery on a post.
Create an awesome gallery with PhotoSmash Galleries in a couple of minutes and then add an option for your visitors to upload images from their own local machine or URL. You can moderate the uploaded images afterwards. Moderated images will be visible under the gallery. Anyone can upload the images from frontend of your site, you can choose whether a registered users or anyone can upload images.
When we talk about a gallery CMS on WordPress, NextGEN Gallery is always a leader. You can add Public upload option using NextGEN gallery by installing another plugin named NextGEN Public Uploader. You can’t upload images from URL thru this Uploader, you will have to upload images from local machine only.