Step 1
Create a new transparent document 512px by 512px st 72dpi.
Step 2
To create the comment bubble shape activate the text tool by typeing T, chose Webdings as your font, set it to 350pt, then type (^) as shown below.
Step 3
Next double-click on the text layer you have just created to bring up the Layer Styles Dialog Box. Then apply the following layer styles:





Step 4
Now to create the gloss layer create a new layer by going to LAYER >> NEW >> LAYER in the menu and name the layer "Gloss". Use the paint bucket tool to fill the layer with white.
Step 5
Grab the Elliptical Select Tool and select a region similar to the one depicted below and press Ctrl+X (or Command+X) to remove it.
Step 6
Set the layer blend mode to Soft Light, the opacity to 75%, and the fill opacity to 62% as seen below.
Step 7
Right click on the gloss layer and select "Create Clipping Mask" as seen below.
Thats it!
You should now have something that looks like the comment bubble you see below.

