Social gaming firm SGN only released its first iPhone game last month, but success has come quickly. Between them, its first two titles - iGolf and iBowl - have been downloaded more than two million times.

Both are free, of course, but that only partly explains their popularity. SGN is doing a good job of promoting the Wii comparison, since both games are played by physically waving the iPhone.

Now the company has launched its third title, iBaseball, which continues that trend. You get to play as a baseball pitcher or batter, swinging or flinging the iPhone to play.

The parallel with Wii Sports is clear from these three games (what price tennis and boxing next in line for SGN?). CEO Shervin Pishevar says the company has more iPhone games on the way by the end of this year, as well as updates to its existing games.

It seems connectivity will play more of a role too - unsurprisingly, given SGN's roots in the social games on websites like Facebook. "We are striving to leverage the power of social networks on mobile devices as the vehicle for communication from any location," says Pishevar.

"We see a tremendous opportunity with the viral nature of the iPhone games for connecting people from around the globe. Evidence of this vision is the Global Leader Board which allows players from across the world to compete against one another, sending game play onto international playing fields."