I've been using www.serviceuptime.com for quite some time now and upgraded to premium account but if someone needs free website monitoring every 30 minutes consider this one as it was reliable for me and still is.

Nice! They have really good prices on their premium services also.
I have been using WebsitePulse.com and they have been very reliable, but not as good with the prices as ServiceUptime.com.

serviceuptime is good we have been using a number of month's, chosen over siteuptime. They have been good in adding all my additional feature requests too, multiple mobile alerts to different numbers, alerts after so many failures etc. All the features needed until I think of some more

nice recommendation thanks

Hmm... I will give them a try then. Just signed up for a free account to try things out for this month.

Thanks man this really helped me out!

I still like http://uppanel.com

" 24 x 7 x 365 monitoring
Automatic alert when your site becomes unresponsive
Email alerting
MSN, ICQ, AIM alerting (under development)
Detailed alert message
Notice when site is back online
Remote locations new !!"

And they check your site every 10 minutes (for free). They do premium services where they check your site every 2 minutes (I think. Not used it in a while.)

Of course, www.serviceuptime.com is still a mighty good service. And they have a couple of features Up Panel dont have (such as phone alerts. But if you can check your email using your phone, thats not a problem as far as I'm concerned.)

Well Nice resource rtm! It is really worth a try.