Is there a website or service that can quickly lookup how much bitcoins are there in a given wallet/address, so I can look up my own wallet from a friend's computer which doesn't have the Bitcoin client installed?
You can use Blockchain.info.
Just paste the address you want to check into the Search inputbox and the website will show you all the transactions where that address was involved, as well as the balance.
protected by Bitcoin Nov 26 at 3:06
Thank you for your interest in this question.
Because it has attracted low-quality answers, posting an answer now requires 10 reputation on this site.
Would you like to answer one of these unanswered questions instead?