Working From Home - How Do YOU Manage it?

I "retired" from the full-time working world when my daughter was born four years ago. Soon after, I was able to take on a part-time marketing position with my kids' school, , (hence, the shameless name drop there).  

I'm very thankful I'm able to work from home — it's great to be free to spend time with my daughter when she's not at school, to run the kids wherever they need to be, attend their various school or athletic events, drive for field trips. 

But... it's REALLY hard to get my work done unless it's 11 pm and everyone else is in bed. If I attempt to knock out a few phone calls done during normal business hours, I run the risk of the person on the other line hearing, "Hey Mom, I pooped in the potty!" If I need to spend time during the day on my computer, I get nagged to come play (trust me, we play plenty), and get guilt-inducing comments about "always being on your computer." When I need to attend the occasional meeting, I need to find a sitter, or bring along a reluctant preschooler and that's just not a good idea. 

We've got a basic schedule that works, and quiet time in the afternoon most days, but we're still working on it. I want to make sure I'm giving my best to my family and my employer. What are your tips and tricks for making a work-from-home situation work for you?