Lots' of interesting stuff in this thread!
You may want to look into using websockets instead of ajax requests for getting live prices from various exchanges. I'm not sure if PHP is well suited for the job.
I've developed cryptowatch.com, it's backend is in node.js and I'm also using socket.io to provide push updates to the clients.
Site:
http://cryptowatch.com/Currently I'm just updating prices about once every 5 minutes through a cron job which runs a c++ program that uses libcurl to fetch prices from various exchanges. The prices are then inserted to a mysql database, and the node.js server checks the database about every 10 seconds and if there's a change in the data, it's pushed to the connected clients over the active websocket.
I've changed the fetching model from a sequential one to a parallel one where I use threads to initiate all the fetching of data, which makes it quite faster to get all the price tickers from various exchanges.
The site is also responsive, so it should work great on all screen sizes.
Development was somewhat slow as this was much unfamiliar technology for me. And the site is still just at 0.1 alpha stage.
Thank you for the tip about meteor, I will look more into it.
Did anyone of you look into glyphicons? Ie. vector icons that resize as the window the site is displayed in resizes?
I see there's a link here to a btc glyph icon:
http://fortawesome.github.io/Font-Awesome/icon/btc/Also, lastly are you intending to monetize your sites? And if so, how?
I also liked the trick at
http://ibit.io/ where the price is shown in the tab of the browser, quite neat trick.
I also found a jQuery plugin that was quite nice:
https://github.com/rmm5t/jquery-timeago"Timeago is a jQuery plugin that makes it easy to support automatically updating fuzzy timestamps (e.g. "4 minutes ago")"
If you look at
http://bitcoinity.org/markets, you will see they have implemented such fuzzy timestamps there.
I also noticed that tickers are quite different between various exchanges, and in one instance (btc-e) they'd even managed to switch ask and bid-values in the ticker. There should really be a standard for how tickers was presented, which would make it easier for developers working with API's from various exchanges.