Absolutely. Had mine for almost a year, moving from a Nokia E65 with Talks, and I haven't regretted it. I haven't jailbroken mine, I haven't seen the need to. In any event while not all app store apps are accessible I imagine the likelihood of them being accessible is much higher than other sources, since Voice Over ties into the OS at such a deep level and Apple's coding environment takes this into consideration.
Depending on what you want to do with a phone an iPhone may or may not be overkill. It makes an exceptional multimedia device, the Audible app is perfectly accessible as well as the built in iPod and Youtube apps though the latter really needs a fast connection to the internet to use. Usage is pretty easy, you should get the hang of it quite fast even with butter fingers like I have. Of course some people might prefer the tactile feel of buttons but there is an incredible liberation to being able to actually make use of the screen similarly to sighted users, even with no useful sight at all as I have.
Text input isn't difficult but doing large amounts gets irritating so if you plan to do a lot of typing in I'd suggest a bluetooth keyboard, however normal phone keypads aren't ideal for input either. Another option is Solona's tactile screen protectors which have bumps where the keys should be, the Otterbox case available with it is also excellent. I have an Otterbox case but not the tactile screen protector and highly recommend it for sheer durability.
iBooks is also very useful if you like books, the selection had been quite limited but it is gradually improving. I checked up a couple weeks ago and was delighted to find the Dresden Files novels have been added some time since my last check.
cx2
-----
To live by honour and to honour life, these are our greatest strengths and our best hopes.