I think the lens is fairly reasonable but the focus isnt fast (on either model)? Dont know a lot about it. I decided to go with a 10-22, 30 and 50 instead of a zoom in that range.

Some reviews for you though:

http://www.the-digital-picture.com/Reviews/Tamron-17-50mm-f-2.8-XR-Di-II-Lens-Review.aspx
http://www.the-digital-picture.com/Reviews/Tamron-17-50mm-f-2.8-XR-Di-II-VC-Lens-Review.aspx
http://www.kenrockwell.com/tamron/17-50mm-f28-vc.htm
 

Keep in mind CR Kennedy do price matching for grey imports of Sigma lenses (though cost landed incl shipping but you get same price and Aus warranty). You just ring them up and then can buy them from a local camera store (e.g. Camera Electronic are good)

Thanks for the input and those review sites. Made for good reading. I have a 50mm 1.8 prime already but want a mid range zoom for travelling. If price and convenience werent a factor i would get a series of primes for sure. Cant stand the low appature of the kit at 55mm in low light but find being fixed at 50mm to be irritating at times.

I never would have thought an Aussie importer would price match the grey market imports. I'll have to keep that in mind. The Sigma (even after price matching) is still $200-$300 more expensive than a grey Tamron with VC. The Sigma is a better lens according to the reviews i have read but my budget is tight and i cant see it being $300 better. Especially for a novice like myself. 

go to camera electronics and ask for sol

 go to www.camerasdirect.com.au there are not a gray import i have brought all my gear off them and they are very cheap to

for cameras direct as well , good service and price I bought a D700 Nikon and a 70-200 VRII and couldn't be happier with the after sales service

Mate take a took at the lens i have canon 17-55 2.8. Sharp as anything. Got mine of ebay for $900. It has L series glass in it and image stab for shooting night handheld.

Here is a couple samples done with it....

Blackwall Reach , Perth W.A by Marc Russo (Australia), on Flickr

Penguin Island, Rockingham W.A by Marc Russo (Australia), on Flickr

Fish and chips by the river by Marc Russo (Australia), on Flickr

Floreat drain by Marc Russo (Australia), on Flickr

Floreat drain by Marc Russo (Australia), on Flickr

Forget Tamron they suck. The best photography comes from having the best glass, dont skimp on it or you will just have a pile of crap photos. What do you wan't, a pile of crap or a few awesome shots? That is the decision you need to make. However the nifty fifty is a good start...great lens bang for buck probably the best.

I base my photography decisions on a commercial scale, if you just want snap shots then get a good iphone and save yourself from the expense.

Best lenses but not cheap for a travel bag IMO are:

Tokina 11-16mm

Canon 16-35mm

Canon 24-70mm

Canon 70-200mm

All are fast and crisp to the edge

The Tokina is fucking unbelievable, my fave by a long shot.

Cant understand what Hlokk is on about talking slow to focus on the Tamron, ignore what he said.

Thanks for the info guys. Still think i will buy the tamron as ive done the sums and its all i can afford. I will sell the tamron and get the canon in a few years time (those photos look awesome btw mark, really sharp) when i have the coin to do so. I know the tammy is not the best lens but i think it can provide decent results and will definately be an improvement over the kit. Fathom we all want L glass but the kit you outlined is way way to expensive for me atm hahah.

Another question for the photogs out there. My sensor has alot of dust on it. Done a test at f22 to verify this. Was wondering what method everyone uses to clean the lens? The 1100D doesnt have an automatic cleaning function which is annoying. I'm about to place an order for a pack of 12 Visibledust 1.6x swaps and the sensor solution. Is this ok? or should i invest in that electronic spinning brush thingy also made by Visibledust?

Bahaha Fathom, really? If you cant get good photo's out of the Tamron its not the glass mate.... Photo's using that lens has won me nearly 5k worth of prizes...

I used to have the Tamron 17-50mm f/2.8 non VC version, it's a great lens, dont let people tell you you must by an L. It's focus is slower than the USM Canons but certainly useable, it is also quite loud (in terms of focus motors), in light of all that I'd still suggest it.

The canon 17-55mm f/2.8 is "better" but only if you can afford/justify it. The Tamron is certainly an upgrade over the kit lens regardless.

The non VC is meant to be sharper than the VC, although if you do video (not sure if the 1100D does it) the VC will be worth it.

VC wont be hugely important between the 17-50mm focal lengths so save yourself the money if you want, I never wished I had it when I owned it.

If your going grey I'd consider DWI for the purchase, I've spent too much money there and never had an issue.

Only reason I sold the Tamron was because I bought a 5dmkII and its not compatable with FF, so I upgraded to the 24-70 f/2.8.

Another lens to consider is the Sigma 17-50mm OS which people have been raving about lately, as someone said, CRK will price match grey prices (plus deliver) so sometimes spending a little more on the Sigma is worth it for the warranty, i never had any issues with the Tamron though.