I'd like to hide sim's skill bar for taking snap shots.
By using moveobjects on, I could get rid of it for temporary but not sure if it's a safe thing to do.
Is there any cheats or hack to hide skill bar ?

if you mean the entire bar at the bottom of the screen, you just press the F10 button and it goes away.

If you mean the skilling progress bar when sims are learning a skill like cooking or logic, the only way to get rid of that permanently is for the sim in question to max out that skill. If you enter the cheat 'boolProp testingCheatsEnabled true' on the neighborhood screen before entering a lot, you should be able to adjust skills (and a whole lot of other things) just by clicking on them. Alternately, you can use the InSIMenator, available at insimenator.net if you don't want to have the testingcheats on all the time.

Thank you for your reply.

Yes, what I meant was head meter, the one shows up when cooking or reading, etc..
(not sure the exact name since I play my game in Japanese)

OK, I will test the way but one more question.

I could even select and put the meter into sim's inventory but not pretty sure if it's all right. Is it safe thing to do ?

You could try it, certainly. Just save before you do, so if anything goes wrong, you can quit without saving and your game will be okay. I'm pretty sure that's fine to do but having never done it before, just be safe and save first.

OK, I'll save first then test it.
Everything is clear now, thanks so much.