I. I sent 1 btc to my TradeHill account yesterday morning (7/14) and a) it's not showing at TH most likely because b) it's still showing 0/confirmed in my BTC client.
Did you leave your client's fee settings at their defaults? If you manually force them to zero, it can take a very long time for transactions to confirm.
You can check the list of pending transactions to see if it's been accepted by the network:
http://bitcoincharts.com/bitcoin/My bet is that it has not been. This can be for two reasons:
1) The funds you are trying to transfer from don't actually exist the way your client thinks they do. So the network is rejecting the transaction as invalid.
2) The transaction has a zero fee or very low fee and is unusual in some sense, either because it transfers coins that are very new or it draws coins from large numbers of small previous transactions.
If your transaction has a forced fee of zero and draws large numbers of small inputs, it may never confirm. (If you set the fee-per-Kb to zero and perform a transaction that draws input from about 5 or so sources, it will never confirm.)