I'm not 100% sure how legit this link is by Otogi, but http://www.giantitp.com/forums/showthread.php?100736-3-5-List-of-Half-Breeds has a list of all the half breeds.  The link also tells you what book this information would be in as well so all of it can possibly be confirmed.  

It appears you can do Dwarf, Ogre, Beholder, and unless I'm mistaken Kender are essentially just the Dragonlance/Krynn version of halflings.

> Base
>
> Half-Ogres (Human/Ogre) - Races of Destiny, Savage Species, Bastards &
> Bloodlines
> 
> Decatuar (Elf/Centaur) - Bastards & Bloodlines
>
> Muls (Human/Dwarf) - Dark Sun 3.5
> 
> Feytouched (Humanoid/Half-Fey) - Fiend Folio
> 
> Half-Bugbear (Elf/Bugbear) - Bastards & Bloodlines
> 
> Lasher (Dwarf/Roper) - Bastards & Bloodlines
>
> Lurker (Gnome/Cloaker) - Bastards & Bloodlines
> 
> Spring Child (Humanoid/Dryad) - Bastards & Bloodlines
>
> Trixie (Gnome/Pixie) - Bastards & Bloodlines
> 
> Watcher (Dwarf/Gargoyle) - Bastards & Bloodlines
> 
> Wendigo (Dwarf/Frost Wolf) - Bastards & Bloodlines
> 
> Wretch (Orc/Hag) - Bastards & Bloodlines
> 
> Wyrd (Elf/Ogre Mage) - Bastards & Bloodlines
> 
> Zenthyir (Human/Half-Lawful?) - Monster Manual II
> 
> Maeluth (Dwarf/Devil) - Fiend Folio
> 
> Half-Kender (Human/Kender) - Dragonlance Campaign Setting
> 
> Template
> 
> Half-Dragons (Anything/Dragon) - Monster Manual
> 
> Half-Fey (Anything/Fey) - Fiend Folio
> 
> Half-Rakshasa (Anything/Rakshasa) - Dragon Magazine, Bastards &
> Bloodlines
> 
> Half-Beholder (Anything/Beholder) - Bastards & Bloodlines

Someone let me know if I shouldn't have copied the info from the link over or if I should only have brought the relevant info over.

> Muls (Human/Dwarf) - Dark Sun 3.5
> 
> Half-Ogres (Human/Ogre) - Races of Destiny, Savage Species, Bastards &
> Bloodlines
> 
> Half-Beholder (Anything/Beholder) - Bastards & Bloodlines
> 
> Half-Kender (Human/Kender) - Dragonlance Campaign Setting