I've worked with Jodi Echakowitz on some stuff earlier this year, and she's a very smart and capable lady. Her virtual agency is doing well too.
I liked her blog post today highlighting what you are letting yourself in for if you decide to go the freelance PR route. You can read the whole list at her blog, but here's a few of my own I'd like to add ...
It can get very lonely! Sure, it's great to pick the hours you work, and there's no boss looking into your cubicle, and a wireless laptop is a godsend on a sunny day ... but there's also no colleagues to bump into in the office kitchen, or by the proverbial watercooler. Most interaction and brainstorming is turned into virtual, online collaboration. Webcams are fine, but it's not the same as a physical face-to-face chat.
It's up and down for the most part. You have to grab the "up" with both hands, work your arse off and bank some of that coin because there might just be a "down" around the corner.
It's exciting! You never know what is going to pop into your inbox or Twitter account any time of day, or day of the week -- including weekends of course. Being your own boss means always keeping a handle on things, but you have to take the time to switch everything off sometimes (including your brain) and enjoying some R&R. Come back refreshed and your clients will thank you for it.