I use Picasa for all my photos.
- Go to your Picasa Web Albums
- open the album
- open the picture
- click on "Link to this Photo" on the right (under Tags)
- check "Image only (no link)"
- select the resolution (for example "Medium-400 400px")
- click on the URL under "Embed Image"
- right-click and select Copy or use Ctrl-C (or Apple-C on a Mac)
- paste that URL into the message window here and surround it with IMG tags
Picasa is very easy to use, as I can upload a whole directory of images with just a few mouse clicks and then share them and use them as I like, with virtually no GB limit (as long as you go with the default setting of converting uploads to 1600 x 1200 resolution).