Any planet or system you bookmark in your log pad appears in the map with a coloured circle.
This would be perfect if you can also set the colour of the circle when doing the bookmark.

This way you can have visual access to
-planets with good bonus to explore
-intruders
-allied planets in core

etc..

I know we have mapgen to do that already, but why use an external program when we can set it all in the game itself??
I dont think its a big load for the code

A good adition to this would be to show the bookmark text when you move the pointer over a coloured system in the map (like real bookmarks work in programs)