The New York Times iPhone application has a Tab Bar with five tab bar items. When you select the Latest tab, the app shows the title and abstract/summary in a UITableView.
The view controller that is being pushed onto the navigation controller stack has its hidesBottomBarWhenPushed parameter set to yes. The code would look something like this in the table view's -didSelectRowAtIndexPath.
NSDictionary *newsItem = [newsItems objectAtIndex:[indexPath row]];
NewsDetailViewController *controller = [[NewsDetailViewController alloc] init];
[controller setHidesBottomBarWhenPushed:YES];
[controller setNewsItem:newsItem];
[[self navigationController] pushViewController:controller animated:YES];
[controller release], controller = nil;
Take a look at the documentation for hidesBottomBarWhenPushed.
p.s. You'll probably get more visibility on this question if you add the tag 'iphone' to it.