Yes, I think the solution may be:
http://blockchain.info/address/$bitcoin_address?format=json

Which will return this:

{
   "hash160":"660d4ef3a743e3e696ad990364e555c271ad504b",
   "address":"1AJbsFZ64EpEfS5UAjAfcUG8pH8Jn3rn1F",
   "n_tx":17,
   "n_unredeemed":2,
   "total_received":1031350000,
   "total_sent":931250000,
   "final_balance":100100000,
   "txs":[--Array of Transactions--]
}

And then, I isolate the "final_balance" value

Not too sure how to implement it on a website tho, but I think it might be the way to go...