You can use a cloud storage site like Box, Dropbox, Sky Drive, Google Drive, Mega, etc. and create a public folder for your photos. Then just paste the link from the public folder into your post. Lots of options - what does Imageshack offer that others don't?
Photobucket gives you 8 gb if you get their mobile app. Sky Drive and Google Drive each give you 5 GB, Dropbox is the stingiest at 2 GB, and for me, Box is the most generous because for a while they were nice to BlackBerry owners, giving us 50 GB for free!
All these sites offer automatic uploads from your mobile phone.