I am using a cingular blackberry on an enterprise server. It appears to reconcile only once every 15 minutes. Is there a way to get it to reconcile more frequently.

if your refering to a BIS account it will only scan the POP IMAP HTTP accounts ever 15 minutes, you can of course foce a reconcile now from within messages track wheel reconcile now
I fyou are refering to a BES account its real time with a rescan every 15 minutes on objects missed. usually due to mailbox size mail server load and network conditions

The BES will only rescan each mailbox every 15 to 20 mintues, and durning the rescan it will do an email reconcilation. This is build into the BES, and can not be changed.