So I was just given a {sundial of the infinite} and I'm not sure exactly what it does, or where it would be useful. Anyone have any examples ? Thanks on advance.
Counters all spells on the stack.
Also if I'm not mistaken it gets rid of end steps.
The text in parenthesis says it all. It stops everything and ends the turn. A lot of people like using it in EDH with {Sedris the Traitor King} so their creatures aren't exiled at the end of the turn.
It's pretty much a combo card.
You can use it to counter spells cast on your turn (at the cost of ending your turn), as previously mentioned.
It's most common use though is abuse the Stack. For example, let's look at {Sudden Disappearance}. After casting it, once you declare that you are ending your turn, the trigger to return all of those exiled cards is added to the stack, and players get a chance to respond to it. If you respond to it by using {Sundial of the Infinite}, the stack (namely the trigger to return those exiled permanents) is exiled. Then the turn ends, which it was doing anyway. Those permanents are now gone forever.