Recesses in the Senate today are much shorter, leading some to question the continued need for this clause. Additionally, the clause has been construed by the 11th Circuit in Evans v Stephens (387 F.3d 1220) to include intra-session recesses, which are typically even shorter, as well as inter-session breaks.
In recent years, the recess appointment power was used by President George W. Bush for the controversial nominations of John Bolton as UN Ambassador along with William Pryor and Charles Pickering to seats on the appellate court after Democrats filibustered the nominations. In total, President Bush made 171 recess appointments. After the Democrats took back the Senate, Majority Leader Harry Reid blocked further recess appointments for the rest of President Bush's term in office by holding pro-forma sessions instead of letting the Senate stand in recess.
Last week, President Obama made 15 recess appointments, including the controversial nomination of former union lawyer Craig Becker to the National Labor Relations Board. For a full list of the recess appointments and some background information on each, see this article at the Blog of the Legal Times.