Hello Gijoe
As i noticed you didn't really insert watermark in your update of myalbum so I decided to do it myself.
This hack is for the moment really working only on GD2 because I didn't yet manage to get ImageMagick or NetPBM work on my computer. However all the system is ready. All which is neaded is the code for the watermark to be applied. I have only included the code you inserted for the watermark but as you'll see I have included a few options for the watermark which could be interesting
Concerning what is possible with this hack.
1) You can choose in the preferences if you wish to apply watermark on the new photos. You can either use a watermark image you have already created or use a text
2) If you choose "Watermark Text" you can then insert the text of the watermark. The system will automatically create the watermark from the string you provide.
3) You can choose where you wish to apply the watermark : Bottom left, Bottom right, Top left, Top Right or Center.
Once active, the watermark will be applied to the photo even if you do a batch upload.
This hack has been done on MyAlbum 2.85 with Xoops 2.2.2 but I think it should work also on MyAlbum 2.84.
Concerning when the watermark is created from a string, you may have some problems with white photos because the text which is created has a white color.
In the next release of this hack I will give at least the possibility to choose the color of the text
For the install very easy

: Overwrite your files with those in the zip file and then update your module.
And now here is the (I Hope) very wanted
Hack
Edit 21/08/05: In fact the hack is now working for gd2 and Imagemagick. There is only netpbm I haven't managed to do yet