With the hype surrounding the iPhone reaching critical mass on June 29 in the US, Apple wants to ensure third-party vendors sell accessories engineered to work properly with its multimedia cell phone.

Apple said on its Web site that accessories and products certified to work with the iPhone will carry the "Works with iPhone" logo on the packaging. Although the iPhone may cause audio interference with some iPod accessories, it will have the 30-pin dock connector as the iPod, so many accessories can be used with both the iPhone and iPods, Apple said on the site.

In January, Apple announced it would make available several iPhone accessories, including a compact Bluetooth headset called the Apple iPhone Bluetooth Headset. The company didn't return calls seeking further details. In a FAQ (frequently asked questions) section of its site, the company said most Bluetooth headsets will also work with the iPhone. Apple also said the iPhone would carry a 3.5mm headphone jack, making it compatible with most stereo headphones.

Despite the secretive nature of the iPhone's development, third-party vendors seem prepared for the launch, offering accessories including headsets, screen protectors and cases.

Available alongside the iPhone at Apple stores will be Aliph's $119.99 Jawbone Bluetooth headset with Noise Shield, a headset that uses a noise-cancellation system originally developed for the US military. The Jawbone makes phone conversations clearer by adjusting volume and cutting incoming and outgoing background noise.

The hands-free headset harnesses the richness of the iPhone's screen and multimedia capabilities to provide the ultimate communications experience, said Hosain Rahman, CEO and founder of Aliph. "People are doing a lot more on their mobile phones than before, and demanding a higher level of innovation," he said. The Jawbone delivers the award-winning design and high-quality voice cancellation technology necessary for users to get the most out of the iPhone, he said.

Also available alongside the iPhone at AT&T Inc. retail stores on launch day will be Digital Lifestyle Outfitters' two protective cases for the iPhone -- the Jam Jacket for iPhone and the HipCase for iPhone -- designed to make the device accessible while protecting it from the elements.

The Jam Jacket, made of lint-resistant silicone, allows direct access to iPhone controls, dock connector, headphone jack and touch-sensitive screen. The case can also store headsets on its back. The $24.99 case will be available in four colors -- black, blue, pink and frost. The $34.99 HipCase is a belt clip made out of leather and Velcro that allows users to store their iPhone on a belt. Users will get one-touch access to the iPhone and the headset jack will be directly accessible to listen to music. Both cases are compatible with the 4GB and 8GB iPhones.

Cases from Belkin will be available soon, notably the $29.99 Armband for iPhone, which can store an iPhone during physical activity. It is made from neoprene with a strap and an iPhone holder. Velcro allows the case to be wrapped around an arm or ankle while the user is working out. It includes pockets to store keys and earbuds and protects the screen while allowing users to navigate it.

Other vendors selling cases include Marware, Pacific Rim Technologies and Sena Cases.

Belkin is also expected to release audio accessories for the iPhone. The $10.95 Headphone Adapter for iPhone allows headphones with smaller and larger jacks to connect to the iPhone. The $19.99 Mini Stereo Link Cable is a six-foot cable that connects the 3.5mm headphone plug on the iPhone to another audio device with a 3.5mm audio input. The $14.99 Stereo Link Cable, also a six-foot cable, connects the 3.5mm headphone plug to another device with an RCA input. They let users play music from the iPhone on another audio device.

Taking advantage of the iPhone's converged communication capabilities, Shure's MPA-3c music phone adapter will allow iPhone users to switch between communication and music on Shure earphones. When a user switches from music to a phone call, the module can cancel background sound and start or finish calls without the need to touch the phone. This $39.99 module works only with Shure's SE line of headsets and will ship in August, according to the company.

To protect the iPhone's glass touchscreen, BoxWare launched ClearTouch Anti-Glare, a screen protector that prevents scratches and glare. Sized for the iPhone screen, the film is washable and reusable. A single pack is available for $12.95 from BoxWave's Web site.

Also focused on screen protection is RadTech, which is introducing ClearCal, an invisible protective panel for the iPhone's screen made of Mylar, a polyester film. ClearCal heals scratches and hides minor surface defects and abrasions, making the iPhone screen appear clean and spotless, according to John Grzeskowiak, chief engineer at RadTech. The $9.95 panel can be cleaned and reapplied multiple times. The company is also introducing Gelz, a $8.95 protective silicone case that protects the iPhone from bumps and drops.