(*MAC users, scroll down to the bottom...)

You can print this out, cut it and tape it to the side of your PC to keep it handy! To type the letter, you will

hold down the ALT key, and then, while holding down the <ALT>, USE THE NUMBER PAD to the right of the keyboard (make sure the NUM LOCK light is on or this won't work), type the number and release the alt key.

Á	alt 0193
á	alt 160
à	alt 0224
À	alt 0192
Â	alt 0194
â	alt 0226
ç	alt 0231
Ç	alt 0199
É	alt 0201
é	alt 130
è	alt 0232
È	alt 0200
Ê	alt 0202
ê	alt 0234
Í	alt 0205
í	alt 161
ì	alt 0236
Ì	alt 0204
Î	alt 0206
î	alt 0238
Ó	alt 0211
ó	alt 162
ò	alt 0242
Ò	alt 0210
ô	alt 0244
Ô	alt 0212
Ú	alt 0218
ú	alt 163
ù	alt 0249
Ù	alt 0217
û	alt 0251
Û	alt 0219
Ñ	alt 0209
ñ	alt 164
¡	alt 173
¿	alt 168

For all you MAC users:

ACCENTS/accent aigu:  hold down the option key and the letter e.  Release.
    The next letter you type will have an accent over it.
ACCENTED CAPITALS:  hold down the option key and the letter e.  Release.
    Now hit <shift> and the letter.
    (This usually works with capital letters, but not always.)

Accent grave: follow the above instructions, but use the letter i instead of e.

Accent circonflexe: follow the above instructions, but use the letter o.

TILDE:  hold down the option key with the letter n.  Release.  Type the letter n again.
    Capital Ñ:  hold down the option key with the letter n.  Release.  Type the capital letter N.

CEDILLE: hold down the option key with the letter c. Release. Type the letter c again. This will also work for the capital Ç, just add the shift key for the capital letter.

UPSIDE-DOWNERS:
¿:  Hold down <shift> and <option> and ?
¡:  Hold down <option> and ! (capital 1)