Can I lower fees with stratagy
Regardless of what accounts they are in in your wallet, consolidating/spending your dust may require substantial transaction fees - maybe even exceeding the value of the dust. The major factor that comes into play is the size added to a transaction by each additional input. You can read a lot of info on the Bitcoin wiki about transaction fees.

Here are some strategies for reducing/eliminating the fees:


Include some dust in a free transaction. How much you'll be able to include without lowering your priority below the minimum for a free transaction depends on the coin-age you're spending in the transaction (large, old balance = high priority).
Include some dust in a paid transaction. The 0.0001 BTC per thousand bytes means that if you have a transaction that's only, say, 250 bytes you can add up to 750 bytes of extra data (in this case, dust inputs) for no additional cost.
Transmit your transactions directly to a free transaction relay/low-fee pool. For example, Eligius only requires 0.1 TBC (0.00004096 BTC) per 512 bytes.
Wait it out. If the value of a bitcoin rises substantially, the transaction fee limits will likely be lowered to account for that, so your dust will not be so dusty-looking.


If these all sound like a bit of a pain, that's because Bitcoin isn't really designed for micro-transactions, and much is in place to discourage spamming in the form of "dust".