I can normally be found roaming the Internet as cScott (typically with a lower-case 'c' and capital 'S').
Unfortunately, at times some other villainous scoundrel will get there first, and the name will be taken. In such cases, the following alternatives have been employed:
Of course, not all sites allow mixed capitalisation, and some sites (which shall remain nameless) require that the first letter be upper-case (if you can believe such a thing!), so the specific capitalisation may vary.