It looks to be working for most, but not for all, here is alertra spotcheck on jodohost.com:
Timestamp Location Result Size Time
2008-05-09 07:04:37 EDT Shanghai CHN OK 27.0 5.16
2008-05-09 07:04:37 EDT Atlanta USA OK 27.0 0.21
2008-05-09 07:04:37 EDT Chicago USA OK 27.0 0.30
2008-05-09 07:04:37 EDT Las Vegas USA OK 27.0 0.82
2008-05-09 07:04:37 EDT London GBR OK 27.0 0.99
2008-05-09 07:04:37 EDT Frankfurt DEU OK 27.0 1.32
2008-05-09 07:04:37 EDT Orlando USA OK 27.0 1.94
2008-05-09 07:04:37 EDT Sydney AUS OK 27.0 1.75
2008-05-09 07:04:37 EDT Hong Kong CHN Error N/A 3.27
2008-05-09 07:04:35 EDT Chicago USA OK 27.0 0.36
2008-05-09 07:04:31 EDT Sydney AUS OK 27.0 2.49
2008-05-09 07:04:29 EDT Atlanta USA OK 27.0 0.29