The answer is yes, it's fine to use tables. The general rule of thumb is that if you are displaying tabular data, a table is probably a good way to go. You should generally try to style your table with css as much as you can though.
Also, this pie graph might help you:
alt text http://www.ratemyeverything.net/image/7292/0/Time_Breakdown_of_Modern_Web_Design.ashx
EDIT: Tables are fine. For displaying data. Just like my second sentence stated. The question was "is it ok to use tables". The answer is - yes, it is ok to use tables. It is not illegal.
Since even though it's implied to use tables for data in my general rule of thumb, apparently I must also state that the corollary is that it's not ok to use tables for anything else, even though the poster already seemed to grasp this concept. So, for the record, the general rule of thumb is to not use tables for laying out your site.
