It will depend.  The chargers now days that the electronics you mention each have are made to work with either a 220 or 110 volts input.  Mut you need to confirm this by looking at the end of the charger where it plugs into the wall outlet.  In very small letters on the plastic, seek for what it says as INPUT VOLTAGE.  If only 110 volts you will need to buy a rectifier/converter (your choice), if it says 220/110 or 240/120 volts, you will not need one.
When I came over, I went to Radio Shack, and they had one with a dual capacity, selected by a switch, 500 watts and 6,000 watts, maybe 1.5 x 1.5 x 5 inches in size, and sold for $ 29,99.  I have used it a few times since arrival, since I brought with me in different trips some small appliances not yet available here.

Plug adapters you may have a need.  There must plugs have two flat ones on top with a round ground one on center below.  You can get adapter from that three prone combination to only two eliminating the ground plug and you are in business.  Or get a pair of pliers and cut the ground one off.  Here, there is no ground on home wiring any way.

Like Happy said, check the voltage rating on each plug.  For most laptop plugs and other that convert power to a USB plus (many phones, cameras, ipads, etc) will be ok here.  I have a converter that I only use for stuff like my George Foreman grill.  

As far as adapters, wall plugs like a ground (like Happy said) and you can have problems about having to force the bigger of your two "top flat ones" into cheaper wall plugs.  The good news is that they sell powerstrips just about everywhere here.  They are cheap and fit just about any plug shape without a problems.  So making sure the plug can handle the 220 V is the only important issue.

Good answers above.  Most of my electronics (laptop, camera, ipod charger) worked fine with a simple plug adaptor (which are readily available inside China).  However, a few things didn't (specifically my electric beard trimmer, phone charger, Nintendo DS and PS2).  That's why, for my 2nd go-round in China, I'm bringing a converter or two.  (While I'm sure they exist, I couldn't find any within China).

it looks like you can get an adapter here free if you get 300 points but that will take forever. let me know if you find out where to get one

Ok so you can use both converter and adapter.  The difference is for example i recently brought some hair clippers from America a adapter will work but a converter will stop the appliance from over heating as appliance  s in home country s are used to taking certain voltage without a converter can damage the appliance.  Certain exceptions you wont need to bother may be laptops, phone chargers simple stuff but something that generates a lot of heat may require it .