Although it is entirely possible to appear high in search engines without any Meta tags and many so called SEO professionals will tell you that they are obsolete, this is not entirely true. Search engines are looking for what you have in your page, how do you think Google adds a description to its results? The use of meta tags will allow search engine spiders to easily index what they find, add descriptions to the results, and define what keywords are relevant to content and such. For the simple task of adding them in, it is hard to say that they are truly obsolete. In short Meta tags are not the be all and end all, they do not have a huge effect on your ranking, but they definitely make your page come up a lot neater in search engine result pages.