use tiles. tiles are NOT obsolete.

The big problem with using just a huge bitmap is that when you try collision detection or the like you start having huge problems. Or if you do use the huge bitmap, create an overlay that specifies the attributes of your areas. Something similar to that idea was done in the Rites of War game.

Best example of huge BMPs is Baldur's Gate.

I personally prefer tiles because think they allow a greater variety of terrain combinations if used correctly and tend to use alot less HD & Memory space. Notice how Baldur's Gate needed 5 CD's whereas Age Of Empires I & II both only used 1.

Tiles are a little harder to get working though, but then again, dealing with 'hot-spots' on a huge bitmap is also a pain in the ass too. So...

I'd suggest trying both if you have the time and seeing which you like best and/or which of the two is better suited for your game.

Personally I prefer tiles, because with huge bitmaps you are going to have to draw the same backgrounds over and over again. For example if their is lots of grass in your game why not just have a grass tile and draw the grass once in a small 32 * 32 pixel bitmap rather than having to draw a whole field of grass several times for all the areas in your map. Although I must admit I have never tried the huge bitmap model so my advice is to decide and use which ever one is best suited to your game!
P.S. Tiles are not obsolete!

Tiles rule.

Baldur's Gate is to bitmaps what Neverwinter Nights will be to tiles. Agreed. Tiles are not dead. Just need to get rid of any noticeable seams.

How should I create my world for my side scroller?

Should I use tiles or are they pretty much obsolete?

Should I just use a bmp image that is much bigger than my screen resolution (ex: screen: 640x480
world: 640x4569)

Or is their another, better method?

Thanks

Yeah, who says Starcraft, Warcraft, Ultima Online or Diablo is lame?

Also, if you're using big bitmaps bigger than screen res, some cards don't wanna create the surface.

Tiles look cooooool if you create them to look cooooooool?
Btw tiles are more dynamic, you can use them over and over again...