I find that it takes a combination of tools, the key is a Blackberry and Nagios-<p>Nagios is a tool to automatically check machines for problems- It's very convenient in that I can highly vary the configuration for each machine- Dev machines might only be checked every 15 minutes, where productions machines might be checked every minute.<p>I have it parsing a variety of log files, and sending me emails when it finds different errors, or warnings.<p>The Blackberry is irreplaceable in this context- While I have an iPhone for my home calls and for testing mobile versions of our product, the iPhone mail client is next to useless.<p>It doesn't have any filtering or searching at all- That's fine for emails to friends, but it's worthless for monitoring.<p>The Blackberry, on the other hand, allows me to set a filter for certain messages, such as those with "ERROR" in the subject, to be "Level 1" messages, which I can treat differently.<p>For example, a normal message might vibrate the Blackberry, where as a Level 1 message is set to ring my BB increasingly louder until I manually check and clear it..<p>This ensures that if I'm sleeping, and we have a site-down-event, it'll wake me up and make me respond, even if I'm rather out of it.<p>With the iPhone, on the other hand, it's all or nothing.<p>Ideally, I'd prefer an app using the iPhone's push notification (whenever it arrives), that would allow me to use XML push requests for different alerts.. I could send an XML Warning, Error, or Fatal Error, for instance.<p>I'd settle for an email client with proper filters on either device, though..<p>The second point is search- The iPhone doesn't allow me to search through prior emails, which is ironic given the publicity of spotlight on the desktop. With my BB, I can search by day, sender, subject, etc; This is a necessity when trying to understand the context on a discussion.<p>Third- The BB email is much, much faster. Because it has real push email, I can get messages before they appear on my desktop- This is crucial for alerts. There is no good way to do this on the iPhone, without forwarding all my mail through Yahoo. Zimbra on the server side, connecting to a BES server is a cheap and reliable solution.<p>So far, I haven't been impressed with ANY terminal applications- The iPhone's screen is too small, and too much space is taken up by the virtual keyboard on these, and the BB doesn't include any useful keys, like pipe or backtick on the default screen. Normally, I use the phones to receive information, and then fire up my laptop + Aircard to fix it.