There are several antique shops on the north side of the mosque that sell jewelry, tea pots, old coins, traditional clothing, etc. Be sure and look for Sultan Hamidi 0774282153 in particular - he will happily show off his photograph in the Lonely Planet guidebook, demonstrate any instruments he has for sale, and send you down the block to visit the glassblowers' workshop where many of his wares are made. Bargain hard and in Afghanis!
(http://www.westernunion.com), bagh-e azadi, near da afghanistan bank.
Afghanistan International Bank (AIB)
(http://www.aib.af), bagh-e azadi. this location has an atm but is closed on fridays.
(http://www.kabulbank.af/) has a branch in herat. it also has western union services.