Hi everybody
If you're interested, I've just published a series of posts about a clone of Arduino (mostly Duemilanove), that we (a friend of mine and I) realized and called Serialino.
The idea is similar to Severino, because it's single-sided copper board too: but serial communications are managed with Max232 (and also the 3.3V are available).
It's released under the terms of CC A-SA 3.0; the KiCAD files freely downloadable and modifiable.
Before giving the link, I prefer to ask Martin the permission: I don't know if auto ping-backs are allowed.