Just in case you thought vuvuzelas were only annoying...
Slovenia 1-1 England
I have a feeling one of the US and England will slip up, and the US look more determined. An easier prediction is 0-1 to England, but the turmoil and injuries to the team (specifically in the backline) should take a toll.
USA 2-0 Algeria
See above. Algeria looked okay against England but that's not saying much; the US will see this as a great opportunity to progress and should have a goal or two in them.
Australia 0-1 Serbia
Without Tim Cahill, Australia have struggled to create chances; he's available for this match. However, Serbia are well organized and should play with more purpose. Australia have to win to progress and could leave space at the back.
Ghana 1-2 Germany
Germany can get it done when they need to, and can score goals. Ghana have struggled to score, even though they lead the group. A draw (or even a loss and some luck) sees Ghana through, so they might not be the most adventurous.