As of today (finally), the IRS now will issue applications for Federal Tax ID/EIN numbers over the Internet. You can go to the site by clicking here.
While the IRS calls the number that is given a "provisional EIN," it is actually the permanent EIN, subject only to being voided if the name and social security number of the principal officer (or, as the IRS's site calls it, the "principle [sic] officer") do not match Social Security Administration’s records or the business has already been assigned an EIN.
Third parties may request EINs via the Internet on behalf of their clients. Third parties must maintain in their files a copy of the Form SS-4 signed by the client.
I applied for an EIN this morning and found the site incredibly easy to use. A few small nits: If you use commas or periods, the application will not be accepted. Thus, "Acme, L.L.C." will be rejected until the application is resubmitted as "Acme LLC." Also, the size of some of the blocks for inputing information may be too small, particularly the block for the address.
Although I will miss listening to the selection from Swan Lake ad nauseam while I’m holding on the phone, the site represents a major improvement in service.