I've been running into a recurring problem lately: when I have a lot of work on my plate, and a prospective client comes along, I have a hard time knowing if I have the capacity to take on the new project, and when, and by what deadline I could complete it. Surely this is a common problem among freelancers.
Usually, I just assume that I can do it (better to have too much work than too little), but that's definitely made my life chaotic at times, having too many projects to juggle at once, and having weeks at a time where I had to spend way too much time in front of the computer.
I've looked around for a solution that looks good to me, but I haven't found it yet. So instead, I'm going to solve the problem myself, by making a new tool. Development starts today (design started last week). This yet-to-be-named web-based tool will allow me to schedule the hours I've already planned for each of my projects, keep a tally of those planned hours, and compare that total to the estimated total of hours I've allotted for each project. Then, when it comes time to consider taking on a new project, I'll be able to ask this tool "by what date could I complete another X hours, given that I only want to work during such and such hours on these days", and it will tell me!
Also, it'll give me an iCal calendar I can subscribe to, so that I can see my planned work schedule against the rest of my real-life schedule (vacations, doctor appointments, etc.), and make adjustments as needed.
And when I feel like this tool is working well and making a positive difference in my life, I'm going to make it available to others. I'm excited.