Copying files from web to phone? Is there a reliable way to move files from the web to my phone?

I am with Orange/T-Mobile (Everything Everywhere) and my 3g coverage is really patchy. When we had wifi in the office I used to use Astro to browse a share on my work computer and copy files that way. We have no wifi now.

I've also tried using Dropbox, but when I hold and download, the image doesn't seem to be anywhere on my phone. I thought it copied them into my gallery, but I can't seem to see them any more.

I've also tried emailing images to myself and then trying to download them on the phone.

All of these seem to fail for me, can this just be an issue with my diabolical mobile carrier? Or is there a better way to copy stuff onto the phone without cable or wifi?

Maybe I'll have to buy a cheap cable from ebay? Any suggests for solutions?

Ta
I am using Dropbox and it works fine for me. When you click on a file to see it, Dropbox downloads the content probably in a temp file and it will launch in the right viewer. If you long click an item and select download it will put the file in its own folder on the SD card (SDcard/dropbox) and the file will be available to a file manager such as Astro. If it is not already visible from the gallery application, you can add it by moving the file to the right folder.

I know you already used Dropbox but I would definitely give it another try.