Unfortunately the easiest way photobucket has is to FTP the files in and out. The downside, is you need a pro account, otherwise they put all these limitations on you that makes it difficult/hassle downloading...

http://support.photobucket.com/entries/21105606

Have you decided which hosting you are using?

I do prefer picasaweb over all of them, they do have a standalone app that you can download that helps a lot in organizing and then you can sync to picasaweb... The upside for me using it, is all picures I take on my phone is auto-uploaded to picasaweb so I always have a backup.