How Could I Cheaply Get a Business PH# With Preconfigurable Forwarding?

Alright, here’s the story:
I’m running a business on the side in addition to my perfectly respectable, 9 to 6 day job.
I’d like to run an ad, and receive calls from people interested in doing business with me.
I could use my home phone or my cell phone, and either would work to some extent, but what I’d really like would be a way to have calls go to a phone number that would either work as voice mail or be forwarded to my cell phone depending on the time of day.
Something like… you call me before 6, the call goes to voice mail, and I can call you back if I’m off work that day or getting off early, etc.
Between 6 PM and bedtime, I’d like to have it ring my cell phone, and of course after that, send it to voice mail.
I’d also like the number to be portable, if at all possible, so that I could put a dedicated cell phone on this line if business warrants.

I know the obvious solution would be setting up a second phone line at the house and hooking up an answering machine, manually activating and deactivating call forwarding when I get home and then again at bedtime, but I’d rather not spend the time.
Cost is also an issue here.
Any suggestions?

Get a second cell phone line and phone. if you want it to go to voice mail, leave the phone off. If you want it forwarded, set the phone to forward. If you want to answer it, answer it.

Keep in mind that forwarded incoming calls cost money per minute to the line that does the forwarding (for business lines on the Verizon network anway). The call to the number is free for you, but the forward is like you calling out.

I ditched one of my forwarding numbers when I realized that most calls were telemarketers running my bill up.

We use www.freedomvoice.com for our business, which will let you do all sorts of cool things - like forwarding on a schedule. No phone lines involved. Best part is that it’s a toll-free number.

I’m not sure it’s 100% cost-effective for a small business but it works ok for us.

I also think Vonage lets you do call forwarding and that might be cheaper than Freedomvoice.

Thanks, Zipper!
Handy service, not quite cost-prohibitive for my business, but… kinda’ borderline while I’m at this stage of business development.
I’ll see what else comes in.