Article writing for computing related subjects

Require article writing for computing related subjects, mobile computing, data security etc. For submission onto article directories such as ezine articles, buzzle, bukisa etc Submission will take place by myself. I simply require author to write the articles for me. Articles will be priced competitively. for a 500 word article. Please bid for one article, this will be an ongoing project, perhaps 2-3 articles per week. But this project is simply for one article, to gauge quality of work. Where possible please provide references to exisiting work.