What's the most effective way to duplicate an instance on SQL 2008? We've got a simple database instance with just enough data in the databases to keep it useful, and we can use it for demonstration purposes, and I want to put a copy of it on my laptop so I can use it for dev work when I'm not at the office. (The regular dev database instances are about 150GB, this one instance is 3GB)

What's the most repeatable/scriptable method for recreating the instance on my laptop? I'm sure I'm going to have to run through the installer again for SqlServer2008, and set up an instance, but after that ... I'm thinking I want to be able to drop my old databases every month or so and copy all the new stuff over to my laptop, as my instance won't change on either the one demo system or the laptop. But the databases themselves will update, with refreshes on the sprocs and the like.

I've considered scripting all the "drop database-files; add database-files {path}" and keeping them in a runnable batch file of some sort, and then I can "drop, delete, copy, add" but wondered if there was a better way than just xcopy and batch?

I'm trying to do this on the cheap (don't we always try and do things on the cheap) so I'm not particularly interested in RedGate products or the like. I want something I can maintain easily in a text editor for myself.
You've hit the nail on the head: copy the files. I've used this to good effect.

I'd say you have to define "cheap" to include investment of time to prepare a solution that doesn't involve xcopy