Is it possible to program iPhone in C++

Although Objective-C does indeed appear to be "insane" initially, I encourage you to stick with it. Once you have an "a-ha" moment, suddenly it all starts to make sense. For me it took about 2 weeks of focused Objective-C concentration to really understand the Cocoa frameworks, the language, and how it all fits together. But once I really "got" it, it was very very exciting.

It sounds cliché, but it's true. Stick it out.

Of course, if you're bringing in C++ libraries or existing C++ code, you can use those modules with Objective-C/Objective-C++.

Short answer, yes, sort of. You can use Objective-C++, which you can read about at Apple Developer Connection.

If you know C++ already, learning Objective-C would be pretty simple, if you decided to give that a try. More info on that topic is at the ADC as well.

I use Objective-C to slap the UI together.
But the hard guts of the code is still written in C++.

That is the main purpose of Objective-C the UI interface and handling the events.
And it works great for that purpose.

I still like C++ as the backend for the code though (but that's mainly becuase I like C++) you could quite easily use Objective-C for the backend of the application as well.