Yes, you can use it in speaking. In fact, you never say "etc" in speaking, you always use the full words "et cetera". The "c" is pronounced like an "s". Instead of saying "et cetera", you can also say "and so on" or you can say "and so forth", etc.

Etc means et cetera. et cetera is used at the end of a list to indicate that further, similar items are included.

etc = et cetera http://en.wikipedia.org/wiki/Et_cetera