Beware of LAStools. That’s a great piece of software, but if you use the “unlicensed” version you should know that the software adds random errors in your data.
From the license file you can read :
The point limit is fairly low (don’t remember the exact value), which means that if you use it for scientific purposes you want to buy a license.
Obviously for “toying around” this is a marginal problem, but when I train people for LIDAR data processing, I feel this is something they have to know since most people are not aware of this.