Post and Beam Shed

I've run out of room in my garden shed. A new little shed would help handle the overflow. I have a substantial stack of railroad ties that I want to turn into a post and beam shed frame. The timbers were originally part of the front walk here at ranchero indebto. I removed the timbers last summer when we had the walk redone. Now I'm thinking that a post and beam frame would be the perfect way to solve two problems (1. get rid of that stack of timbers, and 2. build a new little shed without dropping anything on the framing lumber).

The trick will be in fastening the posts. It would be cool to experiment with some honest-to-goodness post-and-beam joinery. Alas, I don't have the tools for the job. Could this be yet another marvelous case for the job justifies the tools? :)