I always put meta keywords on my sites pages. But I have heard rumors that you do not have to do this. Should I continue putting keywords on my pages or is it just a waste of time?
Well it's true that crawlers such as Google use much more sophisticated methods than simply META tags to decide PageRank and index pages, but I don't think that's any reason to necessarily remove them or not include them.
Other, less sophisticated crawlers may use it as a legitimate source of information, and so I suppose the only clear answer I can give is: if you don't want to limit your visibility to only the well established search engines which don't rely on the tags, then you might as well still include them. As long as you take into account that there are far more important methods of promoting your site (See Google Webmasters Education for example), you'll be fine.