I've copied over the sol-11_2-text-sparc.usb file to a USB thumb drive, plugged into a USB port on the front of the server, and then attempted to find the drive with
ok show-disks
to no avail.
Is there a different way to copy the image over to the drive using a Windows workstation? Is there anything else I should be doing in order to make sure that the server recognizes the USB thumb drive?
Booting a SPARC from USB is not something I've done but I would say that, in all cases, the 'bios' or equivalent must support such a boot if it's to work.
Before the O/S is running there are no drivers installed so it has to be the service processor that is looking for a USB image to boot.
I would simply use the ILOM to mount an ISO image of Solaris to the server and boot from there. All you need is an IP address for the ILOM and another computer to access it.
I did (thank you!) but no luck. Running the ok prompt command devalias shows no USB devices and I've tried all of the USB ports. I am leaning towards DukeNuke's suggestion but still working my way through this.
I genuinely appreciate the help offered from those that have chimed in so far.
Take a look at pages 12 & 19.
What OBP version have you got?
Read somewhere that 4.72 is the first to support USB boot.
What version of Solaris are you trying to boot?
Good catch (see below) but now I need to get firewall rules opened up so that I can upload the new firmware. Thank you!
{0} ok .version
Release 4.36.1 created 2014/06/26 12:20
---------- Post updated at 01:06 PM ---------- Previous update was at 09:31 AM ----------
***Update***, hicksd8 is close on his recommendation. However, OBP 4.27 is the minimum version per this article and this server does meet that standard but it does not recognize any USB thumb drives inserted so far.
I have had no luck so far. I believe that mounting the USB installation image from another box might be my best approach.
To clarify, my situation is that we have AI instances on our local IPS boxes. However, we have issues getting ports to said IPS boxes from our new servers that we must build. I have been tasked with finding a way to avoid making and waiting on requests to open up ports as our security team is not only slow but often works in a.....not detail oriented fashion 
I'd feel safer installing from a CD/DVD ISO image if that's what you're going to do. I don't know what the differences in the images are, but a USB image might not work for a CD-based install.
Probably easier to run a long ethernet cable and just jumpstart the servers from your AI/IPS servers.
But you're allowed to install software from USB drives you fill up with bits you download from the internet?
Oooooh-kay.
I cannot physically run a long ethernet cable from the IPS server to this new server.
Insofar as the downloaded software, I agree with the silliness of the matter but the situation will not change and is out of my hands.
So it seems that your OBP version should be okay for booting from USB.
(Apologies for the confusion over V4.27 vs V4.72, I must have remembered it wrongly).
So you have downloaded the Solaris 11.2 USB text install file.
How did you create your USB stick from it?? Needs to be created using dd or usbcopy.
did you used it on any other version of Solaris