Upgraded to Android 2.2 Froyo and suddenly can't send images in MMS messages? (Mine just said Sending in the message view and never changed to Sent)
The problem could likely be that the images are too large to be sent (carriers usually have a max limit on image size or upload is so slow the it can't finish with a large image) and Froyo dosen't resize the image like 2.1 Eclair did.
To send images you need to crop them first. This will create a new image from a subsection of the original. (Not destroy the image being cropped tho). Do like this:
Open Gallery and open the image you want to send. Press the More button and choose Crop. Select the portion of the image you want and press Save.
You will now have the original plus a new smaller image.
Then, for the new image, do like usual, press Share and Messaging or choose Menu and Attach from inside a message.