It's an exiting adventure, with a lot of adrenaline! :)
If you want to see an other (not tourist) face of St. Petersburg, it's a must do. We climbed a roof in the city centre, where we enjoyed a beatiful view at the whole city; we also entered in "komunalka" (typical Russian flat, where 4 families are living together). After the tour Juri and his friend Fiodor invited me to their place and we ate Georgian and Russian delicious food, we went to the very nice designer shop and we hang out together till the evening. Thanks guys for the nice time!
Authentic, funny, unforgettable experience!