I'm liking the extra editing abilities that Lightroom brings (over picasa), but I'm wondering if I shell out $300 can I use it on as many computers as I like? I know windows generally only allows you to use one key at a time - would Lightroom 3 have a similar restriction? I have a main desktop and a laptop and would like to have it on both if possible.
Adobe Lightroom's single license covers installing it on both your main desktop and your laptop. It even allows you to install one copy on a windows computer, and a 2nd copy on a mac.
From Lightroom's FAQ under "Pricing and Availability."