is there any way to expand it?

Do you mean 140 characters? Or the amount of messages in the inbox?

Wirelessly posted (what does it matter?)

Sms should allow up to 160 characters. That's industry standard

I think it is real annoying only allowing 160 characters. Us there a way that you can allow more to 1 SMS or do you just have to start a new SMS and continue with what you were texting?

There is a reason it is called "SMS" - Short Message Service.

I dont know about you guys, but i have a Curve on TMO and at the top of my SMS writing page it says 160 1/6
Which means i have 160 characters left on that one page (at the cost of one text) with a maximum of 6 pages (as the cost of 6 texts)