Umbrella liability insurance

This may seem like a strange question, but does anyone have an opinion on umbrella liability insurance?  Is it worth it or a way for insurance companies to scare you into paying them more money?  As I start to have some actual assets, I'm wondering if I should consider it as a way of protecting myself against stupid people suing me, since that seems so popular in the US.  If anyone has a policy, how much coverage did you decide to get and why?

Gardens, and cats therein

I have found a source of flagstones for the yard, which will sell them by the pound.  So I will go get many pounds of rocks this weekend, and a viburnum, if I can pick the variety I like.  A week or two ago, I made frolain stop at Mahoney's about 20min before they closed so that we could stand there, in the dark, in the mud, frantically writing down the viburnum varieties they had so I could go look them up online.  I realized the ridiculousness of the position when my sister called. 

Zoe made a run for the back yard this morning while I was putting the flat of seedlings out and had to be fished out from behind the compost pile.  I'm wondering if we should let her be an indoor-outdoor cat.  She really loves the outdoors, and doesn't seem to get enough attention even with five people in the house to play with her.  I believe she was indoor-outdoor before we got her, so she should already have some street smarts.