Virtual earth runs pretty well on Macs! I have personally run it in Firefox on the mac and it is nearly identical to the PC. I have also run in Safari - there were a few minor Javascipt bugs, but nothing to limit core functionality. the main Safari issue
It's a new server product (launched at MDC in San Fran 3 months ago) that gives developers a simple SOAP API to get the real time location of mobile phones on any supported Wireless Network. MLS has a plugin architecture that allows us to build a plugin for
any Wireless Operator who exposes a Location API of some sort. Currently we have Plugins for Sprint, Bell Mobility, TeliaSonara, and Teydo (a location Aggregator supporting 4 Mobile networks in Europe) with more to be announced soon.
Click the link in my sig to see MLS in action and find my realtime-location. I'll be doing a demo/Video on Channel 9 so stay tuned here for more info.
Also Check out Chandu's blog and MLS based locator: