Its time for another weekly peek at the world of protective devices for Apples handsets. From thin to sturdy, weve got a little bit for everyone.

Audioglove: The Audioglove (iPhone 4 and iPhone 4S; $35) features a retractable slot designed to naturally amplify the sound that comes out of your iPhones tiny speaker. According to its manufacturer, the Audioglove can provide up to 20 percent higher volume than the handset alone, and it also enhances the tonal quality of the handsets audio. The Audioglove does not require any batteries, and comes in black, pink, green, or yellow.

BCO Skins: The iPhone 4 Skins (iPhone 4 and iPhone 4S; $18 to $20) are designed to fit over the back and sides of your handset and protect it from scratches and bumps. Theyre made from high-quality 3M materials and come in a variety of different textures and tints, including carbon-fiber (white, black, red, or Digital Camo), wood finish (maple, walnut, or black), and metallic (chrome, brushed gold, or brushed aluminium). Theres even a glow-in-the-dark model, which should make finding your iPhone that much easier when it starts ringing at three in the morning, face down under a pile of clothes.

Caze: The Zero 5 EX UltraThin (iPhone 4 and iPhone 4S; $20) is, as its name implies, really thin. In fact, the company claims that, at just 0.5mm, it is the worlds thinnest iPhone case. Its built of an entirely transparent plastic material, and it features a specially designed opening to help prevent flash glare when taking pictures with the iPhones back camera. The package also includes a thin-film screen protector and a microfiber cleaning cloth.

CM4: The company has added new colors to its Q-Card Case lineup (iPhone 4 and iPhone 4s; $40). The Q-Card, which now comes in Black Onyx, Pearl White, Pacific Green, or Pink Saffire, features a convenient side slot that can hold paper money or up to three plastic cards. It features a soft-touch rubber-and-fabric design that combines great feel with excellent protection.

Ego: The Ego USB Case (iPhone 4 and iPhone 4S; $19 to $50) combines a sturdy protective case with the convenience of a 4, 8, or 16GB USB memory key that slides in and out of a recessed slot at the bottom of the case. Both the case itself and the memory keys are available in black, pink, blue, red, green, or yellow, and each can be purchased separately to match your exact preference, or in a number of different case-and-key combinations.

Griffin Technology: The Crayola Case Creator (iPhone 4 and iPhone 4S; $30) allows you to create a custom case directly from your iPhone using a free app. Starting from a picture of your choosing, you can add doodles and other effects and then (via AirPrint) print the case insert. (Theres also an option to email yourself the newly created case insert in case you dont have an AirPrint-enabled printer.) The case itself includes a number of blank inserts, ready for printing, and features a crystal-clear back that lets your pictures shine through while protecting your handset.

GroveMade: The SkateBack (iPhone 4 and iPhone 4S; $49) answers the question Where do skateboards go to die? Rather than letting them languish in a landfill, GroveMade repurposes them in these colorful backplates that help protect both your phone and the environment. Each SkateBack features cutouts that let you use the iPhones camera and flash, and the SkateBacks come in three color variations: Vibrant, Calm, or Neutral.

InCase: The Leather Snap Case (iPhone 4 and iPhone 4S; $50) features a hardshell construction designed to provide excellent protection, and is covered in luscious, premium leather to give your iPhone a great look while keeping it safe from bumps and bruises. Its available in brown or black.

Mophie: The Juice Pack Pro (iPhone 4 and iPhone 4S; $130) is a super-protective case with a built-in battery that can increase your iPhones life by up to 150 percent. The case is ruggedized for active use, making it a perfect companion for camping and trips to the backcountrywhich, incidentally, is precisely when you need the extra juice the case provides. The Juice Pack Pro features a five-part construction that provides protection from sand, dust, water splashes, rain, vibration, shock, and impacts.

Musubo: The Double X Case (iPhone 4 and iPhone 4S; $30) is made of a soft material that encases your iPhone to protect it from bumps, drops, and scratches, while letting its beautiful design shine through. The case includes a foldable stand for on-the-go entertainment, and it features openings for all of the handsets ports and cameras. It comes in black, silver, or white.

Skinit: The Infinity Case (iPhone 4 and iPhone 4S; $30) features a removable back plate that can be customized using either your own pictures or one of the thousands of designs that the company provides. In addition to the full case kit, Skinit also sells individual plates for $20 that can be swapped in any time you feel like giving your handset a makeover.