Editor's note: Did you pick up an iPhone 4? Go to CNN iReport's iPhone assignment and let us know what you think.
(CNN) -- As iPhone 4 buyers prepared to unbox their new smartphones on Thursday morning, some screamed with joy. Others trumpeted vuvuzelas.
But shortly after testing out the world's new "it" phone, some of those consumers turned to the internet to report problems with the new Apple product.
On Web forums and on blogs, some consumers posted videos and rants about the iPhone 4's new antenna, which is built into a metal rim around the phone and, some claim, causes the phone to get unnecessarily bad reception.
The blog Gizmodo has posted a roundup of the complaints. Several people say that when they hold the iPhone 4 by its metal sides -- essentially, when they're touching the antenna -- the reception gets worse or drops.
It's possible that this is a software glitch and not a real problem with the phone's hardware antenna, Gizmodo notes.
That's a point also made by Walter S. Mossberg of the Wall Street Journal, who reviewed the iPhone 4 this month.
"In some places where the signal was relatively weak, the iPhone 4 showed no bars, or fewer bars than its predecessor," Mossberg writes. "Apple says that this is a bug it plans to fix, and that it has to do with the way the [wireless reception] bars are presented, not the actual ability to make a call. And, in fact, in nearly all of these cases, the iPhone 4 was able to place calls despite the lack of bars."
On CNN's iReport, where citizens submit their own news, Keith Taylor of Sarasota, Florida, posted a glowing video review of the iPhone 4, but he did note issues with reception when he put his hand around the metal antenna.
"It grips well in your hand. The reception has improved, although it's slightly weaker than the [iPhone 3GS] when your hand's wrapped around the phone," he says in the video, which he shot with the new phone. "It also affects the Wi-Fi, but only by one bar, so hopefully not a noticeable difference."
CNN contacted Apple for comment but did not receive an immediate response. When the company's CEO, Steve Jobs, unveiled the new phone at an event in San Francisco, California, he said that making the antenna part of the body of the phone was "really cool engineering."
Some bloggers who got their hands on the iPhone 4 early -- it went on sale in stores Thursday morning but was available by internet pre-order before that -- put the phone through a number of stress tests.
The blog Engadget found that the iPhone is capable of being scratched, even after only a few days of wear and tear. Other owners of the new iPhone have reported that its much-touted "retina display," which is supposed to be among the sharpest in the industry, has an annoying yellow tint on some units.
In an apparent attempt to see how durable the phone is, one man posted a YouTube video of himself dropping the phone on concrete. Similarly, a popular YouTube show called "Will it blend?" promises to post a video on Friday showing whether the iPhone 4 will turn to mush if it's dropped into a kitchen blender.
On Thursday morning, other problems came with the phone's availability.
The phone was scheduled to be on sale at Apple Stores as well as at Radio Shack, Wal-Mart and Best Buy, but CNNMoney reported that most non-Apple stores had run out of the phones and were turning customers away.