Where can i buy cheap digital SLR cameras?

Look at your local camera dealer. The ones that are still around are still here because they offer better service than the big-box stores or mail order. You can usually tell the good ones by watching who's coming and going for a while. If everyone is buying cheapo point & shoots, well, that might tell you something. But if you see professional-looking people moving "big" gear you're probably in the right place. They often have digital gear that's 1-2 generations old. This stuff tends to go quickly, you may want to get on their waiting list or check back often.

Ebay can be good if you find a seller who has a good rep.
I've heard of a lot of people with good experiences with Adorama and B&H Photo & Video. There are MANY, MANY sketchy outfits doing business via phone order and Internet. Check out a site like photo.net for some good guy/bad guy lists.

I already had Canon EF lenses, because I'm a Canon fan...I don't know the nikon or Minolta systems very well. In Canon, you'll be looking for a d30/d60 (same camera, but the d30 is 3mp, d60 is 6mp) but I'd suggest you go for a 10d/20d if you can afford it.

The 10d/20d focus MUCH faster, have much better flash exposure computation, and still use all the Canon lenses we know and love.

Even the current 30d (NOT to be confused with the old d30) is a relative bargain at around $1,200 body only.

The important things to remember are that you can't really go wrong these days. All of the cameras are so good that even the "wrong" camera will still do almost all that you need it to. There ARE some cameras that are better at certain things.

Nikons do flash computations significantly better than Canons.
Canons focus significantly faster and quieter that Nikons.
Minolta (now Sony) and Pentax tend to be less expensive but much less used gear is out there.
Pentax now has "pancake" lenses that are less than 1" thick!
Sigma has its own lenses that are not compatible with anything else out there, so there's no used gear available.

ebay? it depends what u mean by cheap

I agree, shopping at small camera shops will be better in the long run. When shopping on eBay, you don't have any idea of what a seller is like, except by their ratings. These ratings are somewhat helpful, but sometimes the seller gets friends to help boost their ratings.
When you say, "a cheap digital SLR," I'm guessing that you mean absolute cheapest, or near the cheapest. Not something like a prosumer model like the Canon 30D.
Also, when shopping for a DSLR, a large nation wide store is the worst place to go. Most people who work there don't even know what a megapixel is, so how can you trust them to sell you an expensive camera.
Now as for cheap DSLR's, the very cheapest one you can find new is called the Samsung GX-1L. It is the cheapest DSLR, and runs at $450. Look at the website Wolfes.com, and search under Samsung. This is the only place I've seen it, but Wolfes.com does great business. I just bought a Nikon online, and they were great. Another place is B&H. They too are also good, but I dont think they sell the GX-1L.
Pentax has the K100d, a shake reduction DSLR that runs on 4 AA batteries. It's a good choice for beginners.
Another cheap DSLR is the Nikon D40. At Wolfes.com, and most everywhere else, it is $600.
It is also important to know of the used section of DSLR's. Used cameras are cheap, and sometimes you can get an older professional model for the price of a new beginners model.
So once again, try Wolfes.com, or B&H.com

Hope this helped you!

Somethign to understand - cheap & DSLR are two words that will never go together. Mainly because of the requirements to make a DSLR camera requires high production costs -> so in turn, the manufacturers have to sell them at a rather pricey rate.

However, I would strongly disagree with a smaller chain offering lower prices than a larger chain for the simple reasoning of: volume. A company that buys in bulk, pays a lower per unit price and therfor can sell at a lower price. If this wasn't true, companies like Sams Club or Wal-Mart wouldn't be in business.

If you are to go with a company such as eBay make sure you are buying from someone with a high rating AND offers images of the product. Check reviews on that user and see if he has a 95% or higher satisfaction rating.

Also B&H Photo is a great provider on DSLR bodies, lenses and accessories. They also offer a used section for most of their equipment where you may get as low as 45% off an item.

Amazon offers a small selection of DSLR products that are still a great start for someone new to the equipment.

Most places that sell DSLRs offer a package deal which includes a body and a lense. These deals are usually best as they offer a slightly discounted price. Other products to concider purchasing are lenses, tripods, media cards and additional lenses

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You have some good answers already. I just want to add to check the price at B&H Photo or Adorama first. If you find an internet price that's much cheaper, then it is likely a scam. Also check www.resellerratings.com.