To be fair, Megaweb provided good information. For Windows based PCs (and I thought it works for Macs too, it might well do, try it out). What he neglected to mention is that you must type 0169 on the number pad with the num lock engaged, it will not work with the row of number keys at the top of the standard QWERTY board.
A hint open up keyboard viewer from the input method menu (under the flag, if you don't know that, pls RTFM or go thru the help screens)
option and shift key will give you access to a lot of other common symbols via your normal keyboard instead of remember the code page as in PC.
option + ` + a e i o u will give you à è ì ò ù
option + e + a e i o u will give you á é í ó ú
option + i + a e i o u will give you â ê î ô û
option + u + a e i o u will give you ä ë ï ö ü
option + n + a o n will give you ã õ ñ
å is option +a, ø is option + o, ß is option + s... the list goes on and on and on.