I'm interested to hear what characters people permit in the various common fields of input forms (barring e-mail...)
Textarea/Messages: do you allow completely free text, or restrict to alphanumeric and punctuation? I've tried to go the second route, but you always find someone out there that likes using tilde's...
Full name: do you allow anything, or do you use a regex?
Telephone numbers: numbers only
Addresses: alphanumeric, whitespace, hyphens
City/Town names: alphabet, hyphens, whitespace
[NB: edited as requested]