there are good websites given all over, so it's pretty darn hard to look for them when ya needed.
I make this one to save time

start with this
http://community.webshots.com/album/348741035AxIOlt/3
judging from these photos, I think the apartment construction rate in Hanoi is higher than Saigon, and they build nice kicked ass apartments too.....Hanoi new urbans will look so beautiful
saigon PhuMyHung is just kick ass

this is a good website too, has some good old pictures

http://nguyentl.free.fr/html/sommaire_photo_ancienne_fr.htm

more photos of old Vietnam

http://www.postcardman.net
http://www.belleindochine.com
http://postcards.delcampe.com/liste.php?language=E&cat=6556
http://www.indochine-souvenir.com/ or http://www.indochine-souvenir.com/photos/co/monu/

architectures
http://www.nhavui.com

I think Webshots is the best site to search pics ..

Does anybody know where I can look for old pictures of imperial Vietnam?

this is a gơod site for Nguyen Imperial Family

http://nguyentl.free.fr/html/sommaire_photo_ancienne_fr.htm

this is another good site everything/general about Vietnam...in pictures.

http://vietnam.vnagency.com.vn/VNP-Website/Default.asp?language=EN

www.indochina-group.com
a good website about projects in vietnam

Haven't checked this out yet, but it looks promising:

http://www.ibiblio.org/vietnam/vnpic.html

Also:

http://www.farofflands.com/avpa/

http://www.vietantique.com/index1.htm

another good site about Vietnamese arts and antiques.

just a notice for anyone who's interested in old photos of Vietnam
http://www.postcardman.net
has new updated photos of many cities in Vietnam

This one has many photos of new shiny buildings, check out for yourself

http://spaces.msn.com/members/hoiktsvn/

websites of some current projects:

e.town 2 (HCMC)
www.etown.com.vn
Flamingo Dai Lai Resort (Hanoi)
www.flamingovietnam.com
Golden Westlake (Hanoi)
www.goldenwestlake.com
Vinh Trung Plaza (Da Nang)
www.ducmanhco.com
Pacific Place (Hanoi)
www.ever-fortune.com.vn