The file sharing sites I'd strongly recommend you will include FilesTube - since it's one of the largest file sharing sites I know; MediaFire, DropBox, and 4share are also good options to share your files. The only web apps I know of that allows multiple uploads are compatible only for Apple products like PhotoSender and PhotoUpLink. Tumbloadr's site has been going down a lot lately and I've crossed many people having same problems with you. Better to find a good alternative fast. Best of luck!