Eric Lee's www.labourstart.org is running a frequently-updated newswire of global May Day activities.
The site also reports that the ICFTU has launched a "very ambitious venture" for May Day at http://www.icftu.org/displaydocument.asp?Index=991217414&Language=EN&p as (My attempts to load the page have failed. Request overload, I suppose.)
Have a great day, all.
In solidarity,
Brian