In reply to Flicka:
Using Irfanview:
1) Choose File then Batch Conversion/Rename
Then working Down the dialog box
2) Choose the files you want to resize and drag to the left-hand box
3) Make sure you set an output directory different to where the original files are (to avoid overwriting your originals)
4) Choose Batch Conversion.
5) Set output format to JPG. you can change the quality level by clicking options I think the defaul is 80% and this ought to be fine.
6) Select "Use advanced options" and click the set advanced options button. Select "Resize", "Set new size", "Set long side to" and type in 800. make sure "preserve aspect ratio" is selected. and click "ok"
7) Click "Start"
When i tried this i cam out with a size of about 60kb which is fine for ukc (don't worry that it's slightly lower than the size mentioned in the upload guide it'll still be fine in the small size people view at on here)