I'm searching a robot for a 4yr old as birthday present.
Really off-topic but....
I have a feeling quite many webshops are browsed and covered by users here.
Looking SOMETHING like this one:
http://www.hobbytron.com/RC-Roboactor-Programmable-Robot-Robone.html
(must have international shipping as option)
Hi CheapThrills...I can only help you with life-size robots. I think my Lost in Space B9 robot would be a little large for your child, sorry.
Holy Moly !!!
Are the bones of the original 'little person' who operated it inside?
Here is the link. And, yes, I know it's not helpful, but I like extortion videos. :p
What the ... 
About those I linked in first post, I believe they were introduced in 2005, so probably not any more available in too many places...
Too bad, he really wishes for some kind of a robot and I'm not too keen on buying the smallest and cheapest, that will just make him disappoint this time...
That robot looks a lot like robosapien. My boy loved his even after it quit working a couple years ago. Not sure if he still has it. I’m guessing that robot would be even better now.
Maybe not safe for a kid though, never mind the cost.
Lego mind storm is a great toy and can integrate with the Lego he probably already has. Plus the building of the robot is half the fun.
Did you ever find that 4 yr old inside the robot? :P
+1 on this idea, if he is old enough to play with, and has, standard size Legos. My sons enjoy it anyway.
It seems Wowwee don't make them anymore, but there might be some old stock around
Even the RS Media is quite hard to find. I still have one somwhere, along with one of these:
http://www.electrobeans.de/archiv/2007/09/isobot_roboter_von_tomy.html
That's really a good one, but I don't know if it's are still availible nowadays.
+1 on lego mindstorm nxt
it's fun to build it and to program it (on pc you stack blocks of "code")
Aaahhahahah, you so got me! 
Anyway, I´m now checking eBay for those Sobosapiens. Probably getting one used.
It seems like they eat D cells.
Any good links to 3 x AA -> D adaptors or are the only ones available with decent price the 2 x AA ones?
Yes, they use D-cells and they are in their feet. They need the weight of the D-cells there, otherwise they will fall on their nose.
If it's the V1 or his (knock-off) counterpart Robone it needs 2 D-cells in each foot and 3 AAs for the remote control.
If it's a RS-Media (the latest model) it uses 3xDs and 2xAAs in each foot and 6xAAs in the remote control.
Great info, thanks!
I will skip on getting those adapters and use basic D-cells or might just get Tenergy NiMh's.
tested it today. Nice toy and kid likes it but… mileage for one set of D alkies is like 15 feet. It cannot move its legs, if batteries are not full. Tested with Tenergy centura C (stuffed) and no-go, only hands move. I guess it needs more voltage. So, under an hour af playtime equals about 13 bucks invested in a set of batteries… Duhhh…