Yes, hashtags are essentially what made twitter so popular, so much that Facebook copied the model. Hashtags are clickable, allowing users to see what others are taking about who aren't necessarily their "friends" or "followers" which makes Twitter much more newsworthy and interesting. It allows people from all over the world to connect and share their opinions instantly. Like the hashtag, the search tool in Twitter is very powerful. Search any word or phrase and it will pull up every single tweet that includes that word.