NotCom has just updated TinyUmbrella which now support iOS 4.2.6 SHSH blobs for Verizon iPhone 4. TinyUmbrella v4.21.08 is available for both Windows and Mac OS X users and is capable to saving iOS 4.2.6 SHSH blobs for Verizon iPhone 4 as well as all other iOS iDevices. This is a beta release as the developer himself don't own a Verizon iPhone 4 to test his release.
[Update via @Notcom]
To save iOS 4.2.6 SHSH blobs, you don't even need a jailbroken iPhone. All you need is to connect your Verizon iPhone 4 to your PC or Mac OS X and hit the 'Save SHSH' button. Leave the rest to the TinyUmbrella as it will save iOS 4.2.6 SHSH blobs for your Verizon iPhone 4 to Cydia and locally on your hard disk drive.
For those who don't know, Verizon iPhone 4 has already been jailbroken on iOS 4.2.6 using GreenPois0n RC5 B4. Like AT&T's iPhone 4, Verizon iPhone 4 is also vulnerable to Geohot's Limera1n exploit which allowed iOS 4.2.6 jailbreak using GP RC5 but its baseband exploit is yet to be found by iPhone hackers for unlocking purpose.
Download TinyUmbrella for Verizon iPhone 4 from official website.
Download TinyUmbrella for Verizon iPhone 4 (Beta) [Direct Link for Mac]
Download TinyUmbrella for Verizon iPhone 4 (Beta) [Direct Link for Windows]