Uzbekistan finds itself in the curious situation of having a huge trade surplus from its energy exports but also having a parallel black market exchange rate. As of March 2012 the official exchange rate was about $1 : 1,850 som, but the black market rate was around 2,750, making it worth the effort to avoid official exchange offices. However, money changers are hard to come across - better to ask in one of the numerous mobile phone shops, small grocery shops or just at your hotel. The 500 and 1,000 som notes are the most popular; hence, you will be carrying around bricks of currency. The US dollar is definitely the foreign currency of choice.
ATMs do work with foreign cards, but operate at the official exchange rate, and are usually empty. Hence it's better to prepare sufficient dollars to avoid such situation. Some cash machines do dispense US dollars - however, be careful of withdrawing a large number of dollars and then leaving Uzbekistan with more money than you declared when you entered. Be aware however changing dollars to Som is technically illegal, however you will be approached by money changers, just be careful of the over zealous policeman.
In Uzbekistan people traditionally buy goods at bazaars. Prices are fixed in department stores only. In bazaars, private shops and private souvenir stores haggling is part of the game. Bazaars are the best place to observe the daily life of the locals. The Alayski Bazaar is one of the oldest and most famous bazaars of Central Asia. You will find beautiful rugs, silk, spices, handicrafts and traditional clothes in the Eski Djouva and Chor Su bazaars in the Old City of Tashkent.
Typical souvenirs are: