How to see my Picasa albums offline?

In other words how to download a picture from my Picasa album to my sdcard? I can see in the gallery but not have it in my phone :( so I cannot see when I don't have wifi. I don't want full sync but I want to save a pic which I see in gallery easily. Update: I have a good picture in my picasa web album. When I am at my home with wifi, I can see the picture, show it to others. When I go out of wifi connection, If I try to see the picture I wont be able to because the image which was cached will be deleted and no longer available. I will just be able to see the thumbnail. Alternatively If there is an option to save the image to sd card in the gallery image viewer, I will save that particular picture to my sd card when I have wifi and view it anytime anywhere. So now, If I want to download a particular image of mine from picasa, I need to go to internet->picasawebalbums, browse for the same photo I can see in gallery and then download it. Is there a simple way of doing this? May be with anyother app? Else, If I can access the cache folder where gallery caches picasa photos, I can copy from there. But I'm not able to find that too. My phone model: Samsung Galaxy S LCD I9003 ***Update:*** I found this app useful and allow me to save my photos but I cant browse friend's albums yet.