There are more and more things around me where I can use tags for categorizing stuff around and I really like it. Tags a very easy to use and very comfortable afterwards. However I have noticed one problem which I face while setting up tags on different systems: the delimiter for tags in a tag list is different from place to place. For instance in WordPress, tags are separated with commas, while on Flickr spaces are used instead. This makes a problem, because I start using spaces on WP or commas with Flickr and mess up all the tags :(