Andy,
Thanks for your reply - I had a look at your website, and I could use
something like this.  I'd like to use bar charts so activity can be viewed as
discrete blocks of time against the year. Almost need a stacked bar chart (to
account for overlap of peak activity in different departments) but the
durations of peak wouldn't be the same...

Also thanks for your reply yesterday about radial diagrams - I'm still
thinking about the best way to do this as they need to be easily maintainable
(eg add circles on as new tasks come up, change the color coding as projects
progress, alter the positioning of the circles)... at the moment I've got a
word document with each circle hyperlinked to a seperate comments sheet
detailing the projects aims and outcomes etc... and I was just getting a bit
fed up of manula adjustments, and liked the automatic circle spacing on the
standard radial diagram in Excel.

Thanks for your input, Mel