As Dave said, syslog_info on Solaris will get you messages as close to real-time as possible without a sniffer. On Windows, though, our syslog receiver buffers messages as to allow for more scalability. Some of the features of the buffer can be tuned to allow messages to show up more quickly in the syslog.log.
However, depending on the rate of incoming syslog messages, you may still see gaps of minutes between when the syslog message arrived on the server, and when it is written to syslog.log. Fortunately, that is being addressed as part of an upcoming fix for CSCse90599.
