Let say I have a few dozen photos already on in my portfolio I wish to add a specific keyword to, is there a way to do this in bulk or must I do this one by one ?

I think that you could do it quite easily using Deepmeta

^^^ do you know how ?
Couldn't figure it out.

I'll just go and have a look and see if I can work it out.
Sorry, just tried how I thought it could be done and it was impossible.  I thought that you could select a few images and edit them all by right clicking on them an choosing edit option.   It would still be much easier to edit each individual file from deepmeta and then send the edits from there as the IS site is so slow.

Put a new image into DM. Doesn't matter what it is. Remove all keywords/titles/etc.

Put in keyword(s) you want to add. Copy from that file and paste to multiple selected files. Make sure you only select the fields you need, and don't have the overwrite box ticked. Works the same with description fields etc.

Try it with one or two files first to make sure it's right! Don't blame me if it doesn't work!

ETA with keywords IIRC you either have to add ALL the keywords you want, disambiguate, and tick overwrite, or disambiguate the words in each file if you only put one in and don't overwrite. As I say try it with one or two files first until you're sure it's right.

Yeah, read the ETA I've put above too. It's a bit fiddly, but it's a workaround.

There was/is an issue that you have to "save" your additions/corrections twice before the IS servers will accept the changes.
http://www.istockphoto.com/forum_messages.php?threadid=57564&page=261

ETA: It still shows on the Dec Bug Thread

Changes to the file description do not take effect until they are saved a second time. e.g. If a contributor wishes to add a new piece of info such as a lightbox to the description area, they must first make the edit and click on save and then click on continue and then repeat the whole process again for anything to happen. 10OCT12 KJ

Thanks for that. I knew there was something weird happening when I tried to add some LBs a week or so ago.
Teach me to read the bug thread!