need walkaround lens...

Hi..
I own Rebel T1i kit and sigma 50/1.4... Now I wanna change may kit....
I almost all the time use sigma 50/1.4, but it's too narrow for travel photos, for which I want to have a special lens.

I did a statics about focal lenghts I used during travelling, and about 70% were done at 18mm.... So I started to think about an ultrawide lens and ended up with sigma 10-20 (also can't decide old or new).. But I shot a lot of people, including me, and a lot of people started saying I will be dissapointed with it for portraits (I mean portraits in front of a building, view, where a person occupies small part of the picture)... And isn't it too short for travel (but I think for a nice portrait I can switch my sigma)??
Do you think it's a good choice, or a better one will be 15-85? or tamron 17-50??
I can spend about 800$...

If you reccomend a lens, could post a seesion with this lens (I mean about 20-30 from a walk, not just best one)...

Thanks,, I really hope for help....

By too narrow (50/1.4) do you mean too long or it is not a zoom? How can your "statics" say you use 18mm a lot when you don't own one? OOps, I forgot renting and borrowing. Not sure what you mean by portraits where the person occupies a small part of the picture - is that really a portrait? Please, list what lenses you do have now. When people here say a wakaround lens, they mean general purpose which woud be more like 17-50, not 10-20. I like the Tamron 17-50/2.8 for that. Hope you get more help than I am giving. But, also hope no one posts 20-30 pix.

I'd say for walk around 17-50 is gonna work better tahn 10-20 =)

I wrote that I have kit lens...
Yes, sigma 50 is too long for travelling...
I ment "walkround for me"... I can't decide even on type of lens I need.. In my country there is no renting possibillity and don't have friends with an UWA lens.... so I really can't imagine how it is?? Now I like UWA, but I'm afraid I'll become bored after a week/month... So I really think about getting 15-85... But it's to expensive for such lens now.... Also I thought about 17-50 VC, but reviews are dissapointing...
I'm in trouble...

Another alternatives is Sigma 17-70 great FL as a travel walkaround lens

Ah, you have the kit lens, then you might want a UWA, up to you. When you get bored of it, just sell it for close to no loss, think of it as a minor rental fee.

I'm also afraid to do a mistake like I did with sigma 50.. I replaced with it my 50/1.8... And I didn't get and fantastic upgrade!! I would better take an 100/2, which would be something new...
The same thing with 18-55 IS... Will I see the difference with 17-50 (don't say about 50/2.8 and 50/5.6, I have sigma. which is /1.4) or with 15-85??

P.S. tamron's front lens rotates??

I like the 15-85mm but it is expensive. You could get an older 17-85mm and you can buy it used for around $300.

Also check out the Sigma 18-50 2.8 Macro. I've got it (as an upgrade to my 18-55 non-IS) and I think it's a great lens. Supposedly comparable to the Tamron 17-50 2.8 (I've never used the Tamron, so I can't comment).

Tamron 17-50 f2.8