Sorting tasks can be some of the easiest to put together in a short amount of time. All you have to do is have items to sort, labels, and the container. You can pretty much use anything laying around your room to sort. For sorting items, I have used everything from beads, to pipe cleaners, markers, dice, pens/pencils, paperclips, math manipulatives, blocks, pattern blocks, and more. You can find containers to sort in all over the place... at the dollar store, target's dollar spot, or around your school (I found the ones pictured here in old science kits my school no longer uses). I have also purchased ice cube trays and disposable muffin tins at the dollar store for sorting containers!
I found these little animals at the dollar tree. They are great for this sorting task.
I have also used simple things like pom-poms for sorting. The labels for this task specify a number and color to be sorted by.