The delays and uncertainty in submitting an iPhone app to Apple for consideration is inspiring some developers to skip the process all-together and release mobile apps that leverage increasingly powerful mobile browsers.

The latest mobile web apps that have knocked our socks off are from a startup of ex-Googlers called NextStop and the Yahoo-owned events calendar Upcoming. Both offer new mobile iPhone apps that can be updated seamlessly, are available immediately and are a lot of fun to use. Could mobile web apps challenge the dominance of native apps on the iPhone? That's an active debate.

Check out these two hot new mobile web apps, followed by two different opinions from mobile developers about where this market is going. After years of anticipation, it seems that the time for mobile apps has finally come. Now a key question is what form they will take.

NextStop

NextStop is a local review site that has positioned itself as "Yelp for Travelers" but needn't be limited to travelers alone. Though it doesn't have the traction that Yelp has yet, its feature set is far superior. The two biggest differentiators of its mobile site are the ability to view collections of activities near your location and the ability to easily post attractive reviews of places from your phone. Yelp doesn't allow users to publish reviews from their phones but NextStop makes it a joy. User Experience throughout the site is really well done.

NextStop is more attractive than Yelp's iPhone app, it encourages you to put a bookmark on your phone's desktop and there's an integrated photo uploading app coming soon as a work around to that limitation. Once you put that bookmark on your dekstop, NextStop caches a long list of images and javascript so it will load very fast the next time you visit the page. IPhone app? Why bother?

It's a wonder to behold and could become my new first stop for planning an evening on the town, even if I have to go to Yelp for now to check out more reviews of the places NextStop suggests I go.

If you'd like a more in-depth look at the use of HTML5 by NextStop, make sure to check out Robert Scoble's interview with the company.

Upcoming

Yahoo's Upcoming is a great social events calendar. As of today, navigate to m.upcoming.yahoo.com and you'll find the service's beautiful new mobile web app. It looks good on the iPhone, on Android and on quite a number of other browsers that it's on the lookout for as well. It's the kind of interface that makes me want to use Upcoming more regularly!

Bookmark this puppy onto the desktop of your iPhone and you'll have a great way to catch up on upcoming local events when you're on the go. It's all about finding a good interface for users to plug into at the right time in the flow of their day. This is a great example of that - and why make a native iPhone app when you can get all the functionality packed into this mobile web app?

Web vs. Native Mobile Apps

Raven Zachary and Jason Grigsby are two mobile developers based in Portland, Oregon. They worked together building the Obama Presidential Campaign's celebrated iPhone app. After that project was done, the two parted ways to their respective companies. Zachary, who was project director for the Obama app, started SmallSociety - an iPhone development shop that's built native apps for high-profile companies like Whole Foods and Cliff Bar. His company's ZipCar app was showcased on stage at the MacWorld event announcing the iPhone SDK. Zachary is a big believer in native mobile apps.

Grigsby co-founded CloudFour, a mobile app shop that took a very different direction.

"After launching the Obama app," Grigsby says, "we had people coming to us for native apps every day, but we decided we only wanted to do mobile web apps. Philosophically, I don't see any way that web app technology isn't going to be bigger than distributing apps through an app store. As the demographics of users change, you'll find people aren't going to spend their time browsing the app store. They will go to browse the web and they aren't going to install something unless it's heavily promoted. Who's going to do that? Small businesses are going to need mobile apps if they are going to be found at all."

Zachary disagrees, though, and the two say this is something they have friendly arguments about frequently.

"[Users] already browse the web more than anything else, with the possible exception of listening to music," Zachary contends. "Apps appeal to consumers in a way that the web simple doesn't today. The first step is getting a great mobile browser into the hands of consumers. That cuts out pretty much all Nokia, Windows Mobile and Blackberry consumers right away. That's a huge portion of the market. That's going to take years to rollout, and for those consumers to adapt. Meanwhile, iPhone app market keeps growing."

Zachary also contends that gaming will be key. "The mainstream gaming market will always be native. HTML 6 or 7 isn't going to solve that problem. [Because those games require] direct access to hardware. Gaming drives a large percentage of native app revenue."

What do you think? Is the future all about mobile web apps or will most app development continue to be for native mobile apps, now that there are some compelling and widely used mobile app platforms?