Hey Chris- the simplest way of doing a good quality reduction (I find, and if you use a pc of course) is to simply open my photos in microsoft paint and using the 'stretch/skew' function (ctrl+w) can reduce a 2.2Mb to 30 or 40% of it's original size whilst maintaining quality. Obviously if the picture needs trimming the size of the file will be even further reduced.
This picture

began life as 2.2Mb 5megapixel image.
I would suggest photoshop or paintshop for any other manipulation of the image - even trimming in MSPaint is a chore...
Hope this helps.
MC