Entry into Uzbekistan, Kazakhstan and Kyrgyzstan requires the following:
~ 2 black and white photographs
~ Letter of invitation (or sponsorship)
~ Valid visa
A visa will not be issued without the letter of invitation, which can be provided, at a cost, from travel agencies. Certain companies are also authorized to furnish letters of invitation.
It is advisable to have a passport, which will be valid for the duration of your trip, extending for 6 months after the visa has expired. Visa extensions are possible via the Ministry of Foreign affairs, Consulate Department. Visas are issued within one week. Urgent visas are normally issued within 1 or 2 days, after receipt of correct application information.

Kazakhstan
Visa:
$65 Single entry visa
$70 Single Entry Visa Urgent
$155 Multiple entry visa
S165 Multiple entry visa Urgent
If staying more than 3 days in any of the above countries you are expected to register with OVIR (Offices of Visas and Registrations).

Uzbekistan
Visa $40-60
If staying more than 3 days in any of the above countries you are expected to register with OVIR (Offices of Visas and Registrations).

Kyrgyzstan
Visa $45-$60 Single entry ONLY In theory, if you are traveling to Kyrgyzstan for less than 72 hours, a visa is not necessary. This practice is not advised though.
If staying more than 3 days in any of the above countries you are expected to register with UPVR (Offices of Visas and Registrations). A stamp will be entered into you passport, which is sometimes checked on, when leaving the country.