Well you can get thumbnail images from photobucket too...also those that then open up as largerones just select the picture you want (click the box to choose) then click on the generate html/picture codes then you get all sorts of options ready done for you so you just copy paste the best option to use in this case the one that says thumbnail size picture with a link to largeron used for forums
Like this
And it is also quite simple to change the img size in clicking the img in photobucket and then edit and resize it
these are the different options
640x480
320x240
160x120
80x60
Most forums I use are good for even 800x600 pictures and load quite good.
And besides its quite easy to resize them with any of the picture programs you use so they are ok from uploading.
I personally hate imageshck and all the nasty pop ups that burst out and slow things down especially for those on dial up. Ok pop up blocker has been invented but still. Also in few forums I use imageshack is not permitted for you as it is probably the most popular and due to its huge usage it sometimes stall the lines and thus stalls the threads where imageshack pictures are used.
Just few observations and opinions. But like it is which ever suits one is the best from him/her.
Cheers
LT