Many years ago I managed to get my own handwriting immortalised as a Windows font, which I could use in any Windows application. It even printed properly too, from any program. The whole process was done by post and took about a week. It cost something like $50 at the time, if I recall.
Which is just one of the reasons why I'm so hugely impressed by a new web-based service that will do the job instantly, and for free.
Head to www.paintfont.com and decide which characters you'd like included in your new font. You'll probably want the standard A-Z, a-z, the digits, and probably a selection of punctuation and accented characters too. Once you've chosen, you can download a template which contains the necessary squares into which you then write. It's best to use a black pen, and to take your time so that you get the best results.
When you're done, scan the template paper and upload it to the www.paintfont.com site. Within just a minute or so, your TrueType font file will be ready to download. Grab it, install it (which is usually just a case of right-clicking it and choosing Install), and your font is now ready to use in all your Windows apps.
If you have children, you could even use the service to preserve their handwriting in order to see how it develops over time.