As said above there's a long wait for GC holder to bring their spouse in the US. But since last few months the wait time has significantly decreased and as per current processing time of DOS (Department of States) the F2A (family preference #2 category visa for spouse of LPRs) processing time per October visa bulletin is Apr. 2010 meaning there is 6 months back logged, but these can be retrogressed in the future. 

The table below shows the current cut off dates for family preference category:

Family	All Chargeability Areas Except Those Listed	CHINA-mainland born	INDIA	MEXICO	PHILIPPINES
1st	15FEB06	15FEB06	15FEB06	15DEC92	01MAR97
2A	01APR10	01APR10	01APR10	01JAN10	01APR10
2B	01APR05	01APR05	01APR05	22JUN92	01SEP02
3rd	01MAY02	01MAY02	01MAY02	22OCT92	01MAR95
4th	01DEC01	01DEC01	01DEC01	08DEC95	01APR91

Furke,
If your friend gets F1 visa and get married here in the US, his wife always can file I-130 for him. The processing time for I-130 is 5 months these days (for all four service centers).

So, according to the current wait time it takes up to 5 months to get I-130 approved and another 5-6 months for visa to become available in his case, after that he can apply for the immigrant visa. BUT REMEMBER THESE PROCESSING TIME CAN CHANGE IN THE FUTURE.
Look at the table below, the processing time of California Service Center.

Form	Title	Classification or Basis for Filing:	Processing Timeframe:
I-102	Application for Replacement/Initial Nonimmigrant Arrival/Departure Record	Initial issuance or replacement of a Form I-94	2.5 Months
I-129	Petition for A Nonimmigrant Worker	Blanket L	2 Months
I-129	Petition for A Nonimmigrant Worker	E - Treaty traders and investors	2 Months
I-129	Petition for A Nonimmigrant Worker	H-1B - Specialty occupation - Visa to be issued abroad	2 Months
I-129	Petition for A Nonimmigrant Worker	H-1B - Specialty occupation - Change of status in the U.S.	2 Months
I-129	Petition for A Nonimmigrant Worker	H-1B - Specialty occupation - Extension of stay in the U.S.	2 Months
I-129	Petition for A Nonimmigrant Worker	H-2A - Temporary workers	1 Months
I-129	Petition for A Nonimmigrant Worker	H-2B - Other temporary workers	1 Months
I-129	Petition for A Nonimmigrant Worker	H-3 - Temporary trainees	2 Months
I-129	Petition for A Nonimmigrant Worker	L - Intracompany transfers	1 Months
I-129	Petition for A Nonimmigrant Worker	O - Extraordinary ability	2 Weeks
I-129	Petition for A Nonimmigrant Worker	P - Athletes, artists, and entertainers	2 Weeks
I-129	Petition for A Nonimmigrant Worker	Q - Cultural exchange visitors and exchange visitors participating in the Irish Peace process	2 Months
I-129	Petition for A Nonimmigrant Worker	R - Religious occupation	2 Months
I-129	Petition for A Nonimmigrant Worker	TN - North American Free Trade Agreement (NAFTA) professional	2 Months
I-129F	Petition for Alien Fiance(e)	K-1/K-2 - Not yet married - fiance and/or dependent child	5 Months
I-129F	Petition for Alien Fiance(e)	K-3/K-4 - Already married - spouse and/or dependent child	5 Months
I-130	Petition for Alien Relative	Permanent resident filling for a spouse or child under 21	5 Months
I-130	Petition for Alien Relative	U.S. citizen filing for a spouse, parent, or child under 21	5 Months
I-130	Petition for Alien Relative	U.S. citizen filing for an unmarried son or daughter over 21	February 8, 2007
I-130	Petition for Alien Relative	Permanent resident filling for an unmarried son or daughter over 21	5 Months

hope that helps !