Help with the loop

on my site when I post something to Twitter, it then writes a post on my blog and I have customised it so it doesn’t look like a normal post using this code in the loop:

<?php if ( in_category('twitter') ): ?>
<div class="twitter">
<?php the_content('Read the rest of this entry &raquo;'); ?> // <a href="www.twitter.com/davemoran">Follow me....</a></div>

I want to be able to do the same if I post from a different category e.g football but I can’t get the php to allow more than one of these arguments, is this even possible to do?

If I make no sense let me know and I’ll re-explain!!

Thanks