Does anybody know of an internet site through which I could find
stocks or mutual funds which recently did exceptionally well, and
stocks that did exceptionally bad?

Hi vaac-ga!
It appears that you are looking for a stock screener or a fund
screener. There are some pages that offer this service, for free. One
of them is Yahoo! Finance. The screener is located at

Yahoo! Finance - Stock Screener
http://screener.finance.yahoo.com/newscreener.html

The Java screener in this page is apparently temporarily disabled, but
you can still use the HTML screener. In the screener, you can choose
some criteria to select stocks. For example, if you want a list of
stocks that did exceptionally well, you could choose "1 year
performance", "more than 70%" and so on. The fund screener works
similarly, and is located at

Yahoo! Finance - Fund Screener
http://screen.yahoo.com/funds.html

You can also try the MSN Money screeners, which seem to offer more
criteria to filter the stocks than Yahoo!

MSN Money - Stock Screener
http://moneycentral.msn.com/investor/finder/customstocks.asp

MSN Money - Fund Screener
http://moneycentral.msn.com/investor/finder/customfunds.asp


Google search strategy:
"stock screener"
://www.google.com.ar/search?q=%22stock+screener%22&ie=UTF-8&oe=UTF-8&hl=es&meta=


I hope this helps! If this is not what you were looking fort, please
don't hesitate to request clarification. Otherwise I await your rating
and final comments.

Best wishes!
elmarto

thanks for calling my attention to the web sites listed.