im looking for a cheap but reliable data projector to use with my laptop.
i have little experience with projectors so i dont know what i should go for.

i mainly require a projector for reproducing scaled artwork on canvas/murals etc.
thanks for any suggestions.

How much are you looking to spend on the projector. Will you require a screen to go with the projector. I got the lastest Harris Technology catalogue lying around some where i will look for it and see what is has got.

I'd have no clue on what to recommend, but for others to help you might need a bit more detail, such as how large the display size is needed, where it'll be located (inside, outside, light area, dark area etc) and also roughly how much you want to spend. A "budget" for you might be sub-$1k, but a 'budget' one could be $2k for someone else, so it would be helpful.

You can pick up something like a Epson EMP-DM1 for about $850 this has built in DVD player or RCA input

for reproducing images on to canvas for doing airbrush type tracing work this should be more than good enough

or are you just after an overhead projector to reproduce slides / tranperancies?

Is colour reproduction important?
I wouldn't think so in this case, but if it is, i'd definitely stick with LCD technology over DLP.
From my experience with cheaper projectors, the LCD's have far better colour reproduction.
The DLP's are better for movies with lots of fast motion, but you're using stills, so I guess it doesn't matter.

Once you get up to the higher end ones, there's less of a gap in most cases.

I've had good experience with Benq's for a cheap, but reasonably decently spec'ed, projector.

Another cheaper option might be to print out the graphics and project them using an epidiascope / epidioscope / episcope / opaque projector.
If you just go for a kids type one (like an Artograph), which still works well, it will probably only set you back about $70.

all i need is a simple cheap projector that i can use to enlarge digital images onto canvas / walls etc. the cheaper the better. reproduction of detail is more important than colour.

I've spent a bit of time looking around and i've found:

SVGA - ViewSonic PJ503D @ www.ht.com.au = $599
XGA - NEC NP100G @ www.lmc.com.au = $649

There's cheaper out there, but this is probably as far down the price scale as i'd go.
Both manufacturers make reasonable stuff and i've used both sellers before.
Like most cheaper DLP projectors, both probably don't have great colour reproduction.
Both projectors are reasonably portable, which is a plus.
I'd probably go for the XGA projector.
Even though it is a bit more expensive, it's brighter, slightly smaller, longer lamp life and the added benefit of the higher resolution.

I was really surprised that I found a 2000 ansi lumen (still quite usable in a moderately lit room), xga projector for $649 (actually, under $630 if you hunt).

Work is looking for a couple of cheapies to cart around, maybe they'll do the trick.

Edit: The site wrongly listed the NEC above as XGA, it's only SVGA.
The XGA model is the NP200G @ ~$845.
Both models are still pretty cheap for what they deliver.

Found another projector to add to the list.

Acer X1160 from umart $663 plus there is a $49 cash back offer from Acer until June 30th so it will be $614. HT are selling it for $799 so you are getting a good deal from umart.