The next best thing – sometimes even better – than being here yourself. Rates in the $25-50/hour range or from $50 per errand.
Or write to email@example.com explaining the nature of your need and your budget.
Speaking of budget, remember that getting to the other end of Moscow is a tiring two hour exercise, and a 30 min. post office lineup is entirely usual. Typically any given task here will take an order of magnitude more time and effort than if done in the States or Canada. My recent purchasing assignment consisted of a trip into the depth of a huge industrial zone, finding an outlet that didn’t bother even posting a sign, filling out the usual forms and signing a serious looking contract, then a trip to the bank to make a payment, then back to the office, and only after that I could go to the warehouse where I got the little package I was after. Another hour and the little box with electronic components for some obscure Russian device was in the mail. The total cost of the package was $70, of sending it $20, and of my services $200.