I use xe.com too and usually find it very reliable (I have also used it to send money abroad without problems). However, just occasionally it seems to get out of sync with the Chilean market. For example, on Monday this week it persistently claimed that the rate was 630 when I was reading in El Mercurio that $1 was trading locally for 640. I tried changing some money (if only I had a crystal ball) and got 639. Afterwards the rate on xe.com went up. This isn't the first time I have seen it show the "wrong" numbers, though it is unusual. I think it must be due to local forex market variations. If anyone has a better explanation or information on a local Chilean exchange rate feed, I'd be interested. I looked at "forex.cl", but it seems to be mainly a (fairly large) trading facility and I could see any rates information there.
As for the El Mercurio link, I use that not to
get the rates, but to try to understand them

. They usually have a quick analysis of
why the peso goes up or down.
Cheers,
James.