Ask HN: How much equity should I get?

About a year ago I began to work for a VC that wanted to explore the twitter universe and see if there was an oportunity to launch a startup. After a few months they came up with an idea and, another programmer and me, started working on the prototype. Nowadays we are near the first version, we are now three programmers, two designers(from an agency) and a marketing guy. When I started working for these guys they told me I will get an equity but I didn't ask them for a number. Im getting paid by month a salary in a similar amount to the market rate.