pagename.domain.com vs www.domain.com/pagename.html

I'm making an iPhone repair site, and I'm not sure what to pick here.

http://iphone4.example.com or http://www.example.com/iphone4.html
Personally I think the first one looks better. But then again the second is more standard and recognizable.
Also, is one better than the other with regards to SEO?

Thanks for any help,
DLA

Generally using subdomains is reserved for sites which are distinct from the main site, so I would recommend /iphone4.

And please don’t advertise commercial services, use example.com for demonstration, which was created exactly for this purpose.

you do have the choice also, of setting your site up as http://example.com
or http://www.example.com. It makes no difference SEO wise as long as you use whichever one you pick consistently, especially when backlinking. Otherwise, google will index it as 2 different sites.

Either way, you might wish to fix these few coding problems: http://validator.w3.org/check?charset=(detect+automatically)&doctype=Inline&group=0&uri=http://www.iana.org/domains/example/