Question: I keep accidentally dragging windows into other workspaces on my Macbook Air running OS X Lion.

Can I disable dragging into other workspaces or make doing so more difficult?

Answer: 
There's a hidden preference for adjusting the delay in seconds:

```
defaults write com.apple.dock workspaces-edge-delay -float 0.5
osascript -e 'quit app "Dock"'

```

It can be set to an arbitrarily high value to disable dragging windows to other spaces.
With the [Warp pref-pane](http://www.ksuther.com/warp/), you can set a delay and/or require a modifier key(s) to allow a space change.