(I was too lazy to type this earlier... lol)
Ok, so you're looking at the image you want to get full sized. Click the Print-at-Home button above the image. Click the Get Started button. In the popup window, right click and click View Page Source or the likes (I don't know about IE)
Now you're looking at the page source. Not too far down (about 28 lines) you'll see 4 javascript arrays. You want the link(s) from the arrImgLandscape array (or arrImgPortrait, depending on the picture orientation). So basically look for the line that says
arrImgLandscape[0] = "http://us.f6.yahoofs.com/users/randomstring/__hr_/afile.jpg?randomstring";
copy between the quotation marks and paste in the address bar of your browser. Full size image
This can be done for multiple pictures at once as well... use the checkboxes in the album view and follow the same procedure from there on. The image urls will be arrImgLandscape[0], arrImgLandscape[1], arrImgLandscape[2]... and so on, one for each image you selected.