About an hour after the announcement I found something called Rhodes, but using of Ruby and that all 'Network synchronization' stuff effectively deterred me.
What I found next was PhoneGap. Quoting creators:
PhoneGap is an open source development framework for building cross-platform mobile apps. Build apps in HTML and JavaScript and still take advantage of core features in iPhone/iTouch, iPad, Google Android, Palm, Symbian and Blackberry SDKs
It was everything I need. It seems that it also supports Symbian. My first try was 'Get Started with Symbian (Qt)' part from the tutorial. I installed another tons of useless stuff (really - it was another 20GB to make it 'works').
I did my best but nothing seems to work properly or even close to. I googled thousands of different forums, blogs, tutorials and manuals with no result. I even try to search for my answers on Stack, where i found nothing. So I asked new question in there and few hours later I got the answer (from one of the phoneGap developers), from which i concluded that it simply doesn't work. Fine. So I had to write something on my own.
One of the methods that come to my mind was to render HTML/JS in simple browser-like application. It is possible for example using WebKit.
Tired of installing millions of plug-ins, libs, etc. I download Nokia SDK All in one Beta and start new 'Mobile QT Application' project in Qt Creator.