this has limitations.. however, if u are in the office, u may install a Linux watch dog called Big Brother.. it supports ping, SNMP, SMTP, POP3 etc checking.. and will primarily send u an e-mail when it detecs the service is down...
why i say it's limiting, is because u will need to be in the office for u to receive that e-mail.. remote notifications, such as SMS or pager, would mean u would need to install a mini SMS gateway at your office, with a cell phone or GSM modem attached so it can send u an SMS when the service goes down... of course, for this, most of the hassle is in interfacing the software with your applicaitons.. which is simple once u get the hang of it... however, if u go for a cell phone connection, this will be cheaper than a GSM modem, as it already has a wireless connection to your wireless network provider.. a GSM modem or a permanent leased line circuit to your wireless provider would be more expensive......
it depends on how far u want to take the notification... e-mail is the most cost-effective, but u may want to be on the road alot... and u can only send an e-mail to your local machine, as there won't be a link to send an e-mail to a remote office...
good luck...
