Get a (down)load of these addictive iPhone apps

— -- iPhone owners looking to spice up their summer can find more than 50,000 applications at Apple's popular App Store. And the word "popular" isn't used lightly here; more than 1 billion apps have been downloaded for the iPhone and iPod Touch in the store's first year. Apps range from the silly (digital whoopee cushions) to the sublime (classic novels in the public domain). Here's handful of fun-and-games apps for summer:

Jules Verne's Return to Mysterious Island, Chillingo; $4.99. Adventure games, which focus on exploration and puzzle-solving, are in a bit of a renaissance thanks to the iPhone, with versions of Myst ($5.99) and Dream Chronicles ($2.99). Return to Mysterious Island, a challenging 5-year-old PC adventure based on the Verne novel, has gone pocket-size (though it's a hefty 263MB download). Navigate with your fingertip through this first-person game as Mina, a young sailor stranded on an island; survives by finding and combining items and solving the isle's mystery. Also check out Chillingo's fun puzzler, Toki Tori ($4.99).

Peggle, PopCap Games, $4.99. It's one of those puzzlers that's easy to pick up yet impossible to put down. PopCap's celebrated PC game is now available for the iPhone and iPod Touch and features nearly 100 levels of ball-bouncing fun. Peggle might be described as a digital Pachinko, in which you must choose where to shoot a ball at the top of the screen and watch as it cascades down, hitting colored pegs and bumpers along the way; if all the orange pegs are touched (and thus destroyed) with your limited number of balls, you advance to more elaborate stages.

The Moron Test, DistinctDev; $0.99. How much would you pay to see how smart you are? For less than $1, The Moron Test features a collection of more than 100 brain-teasing puzzles that challenge players to see how many they can solve — and vie for best time as well. For example, you might be asked to tap five yellow ducks in order from largest to smallest (based on body size or eye size) or quickly add up a few numbers and then tap the correct sum from among four options. This clever game is also fun to pass to friends to see how they fare. Scores range from Moron to Genius.