1. Your Current Job
Start with the simplest possibility: making your current job fit your new reality. Look at the parts of your job you do alone and those that might benefit from being completed while co-workers are not on the job. For example, when I worked as a copy-editor, it was to my employer's advantage to have me working on manuscripts at night when the office was closed and getting them ready for the next person to look at first thing in the morning. I was able to work in the office during school hours and at home at night to finish my eight hours. Read Write a Work Flexibility Memo for some ideas on how to request this.
2. Your Current Company
If your job doesn't lend itself to out-of-office work, take a look around at other jobs you might be qualified for that would offer a benefit to the company if done outside of normal hours. Peruse the company's job listing for anything that would be appropriate for a work-flexibility proposal. Look at tasks that are not being done efficiently, and consider whether a freelance job could be assembled that took those tasks off the desks of people who would perform better without them. Consider the sort of consultants your company hires, and whether you might do the job better than they could. If you're a valued worker, your company may be willing to put something together for you rather than lose you -- particularly if it's to the company's benefit.
3. Your Current IndustryCompanies are increasingly using freelancers and consultants to do work out of house. If your company is unable to make more flexible use of your services, it's possible that another company in your same industry might value the expertise you could bring. Starting your own consulting or freelance business means learning to live without benefits and predictable income, but it significantly increases your flexibility and your ability to work where it's most convenient for your family. Make sure that leaving a full-time position won't put your child's insurance in jeopardy; flexible jobs often work best when one spouse stays in a traditional employment set-up.
4. Your Own BusinessHave you figured out how to do something or make something for your child that you think other parents of children with special needs might be interested in? Many enterprising parents have started their own business to spread solutions, advocate for children with disabilities, and find flexible and meaningful work for themselves. Read my Enterprising Parent profiles for more information on how these parents have gotten started, and then consider whether your family has some expertise or creativity that could be put at service of others in your same situation. Depending on the endeavor, you may be able to start small and low-risk and grow your business along with your children.
5. The Internet
The Web has become a fabulous place for parents of children with special needs to meet, connect, and share their experiences. If all you need from work is a creative outlet and a way to put your talents to good use, starting a blog or a website or an online community may be just what you're looking for, and services like Blogger and WordPress and Facebook make it easy and free to get started. However, if you're hoping to make an actual living -- or more likely, a useful second income -- you'll need to look around a little more carefully. One place to check is About.com, which I can recommend as a good place to share your passion and expertise and get paid for it. About.com is now hiring writers for guide sites and topic sites, the latter being less of a time commitment. Many About.com guides are also parents of children with special needs -- read interviews on how they balance About.com work and caring for their kids.