I love jQuery DataTables. If you're not familiar with this library, it's basically tables on steroids. I use it often just for it's built-in sorting, filtering, download buttons and nice api. It's always a real quick way to get fully-functional tables on the page.
Recently, I had a client request to add footer totals to the bottom of each table. Whoa, I thought, Wouldn't it be nice if they updated when you searched?.
Yeah, I mean, wouldn't it suck if they didn't?