Original images are 2000x1400px in size and still look sharp on my phone.
There's sometimes a few secs pause with first page, but rarely after that, unless you resize browser.
to see what it sees at your site. The cached page of your front page is an XML error.
Also I don't see the site scaling images to match my browser unless I enter the site with a large window. If I go to the link with a small window and decide to resize after the image loads, the images never grow to match my window. See the screen shot. Both Safari and Firefox show this behavior.
It seems you are serving an HTML gallery to the phone. I got the server to send the html gallery to my desktop to see if you were in fact scaling images on the back end in the html gallery. You're not. They look good on the phone because the screen is tiny. The server is sending 1200 pixel images (at least the one I saw) which then get scaled larger to match the screen. Worse, the 140 pixel thumbnails on the front page are getting stretched to about 500 pixels on my screen with obvious consequences.
None of this is to say the site is bad, just that you haven't solved the problem I was talking about.