I'm not aware of any way.
The only slightly
simpler ways I know of to set up wishlists are:
1) Have the TiVo create it for you from your title search results. (On Premieres in the high def menus, or on TiVo S3/HDs in the TiVo Search Beta you're offered the ability to have the TiVo autocreate a wishlist.*)
2) Use a better keyboard. (Instead of using the normal "Ouija board" with the navigation buttons)
2-a) Use the TiVo Slide remote with it's full keyboard.
2-b) plug in a USB keyboard to the TiVo
2-c) Use one of the TiVo Apps for android or ios devices and use the apps's virtual keyboard.
That said, a true online wishlist management ability (including hopefully the ability to transfer them to other TiVos on your account; like they added for season passes) would be very nice.
*Be careful of special characters. In my limited experience with this feature I've noticed the TiVo doesn't sanity check for them, so it can create an 'invalid' wishlist that won't ever match anything