One weird thing when logging in to JLI, is the fact that you don't have or are an avatar. You move your camera around and you can even put animated avatars there, but you yourself are not yet rezzed as an avatar. But, this will be available in an upcoming release, according to an announcement on the site.
Speaking of moving the camera: this is done by rightclick - drag, just like in Eve Online. I like this very much, and miss it dearly in Second Life.
Another nice thing is the physics: stuff bounces nicely in JLI. We'll have to see how avatar movement turns out when avatars become available.
For those of you who want to share snapshots: I have created a Just Leap In Flickr group.