We're a little late on this one, but you know those Sherlock Holmes adventure games that have been released on the PC for the past few years? Well Big Fish Games has been porting them over to the iPad. So far they've released The Awakened, and The Hound of the Baskervilles. The Awakened is particularly interesting as it's been advertised as Sherlock Holmes vs. Cthulu. Have a look at the trailer.
The games are iPad only and are free to try, but cost $5 - $8 to unlock the full versions. A decent price for a PC adventure game, but when it comes to iOS price, it is a bit hefty. Hardcore adventure games and Holmes fans will probably want to pay it though to have a portable version of the master detective's adventures.