I aim to make this a place to point recorders (vice-county recorders but also anyone else interested in recording plants).
For a start, how about websites providing mapping and geographical information? I would welcome comments - and additions to the list.
Google maps is one of my defaults. It provides pretty good aerial photography, and generally works nice and fast. I also use it for finding places and route-finding as it seems pretty good at finding place-names when you begin to type one.
Bing maps probably aims to give a similar service, but has pros and cons. You can get Ordnance Survey maps down to 1:25,000 scale, which is handy, and I am also quite keen on the "birds eye view" feature, although it is better in urban areas - not so useful for recording.
Cucaera.co.uk is my new favourite as it now has Google type maps, aerial photograph and OS backgrounds, but also shows grid squares which vary in size as you zoom in and out, and also has lovely detailed vice-county boundaries.
Where's the path? is a very nice website (although perhaps a little home-made) which allows you to compare two maps at once - for example Ordnance Survey and aerial photography, but also historical Ordnance Survey maps.
Grab a Grid Reference is similar, but with an extra feature allowing you to display the vice-county boundaries (although based in Bedfordshire it still includes all the Welsh vice-counties).
Get-a-map was an old favourite, providing Ordnance Survey mapping down to 1:25,000. Unfortunately this service has now ended, and the OS have replaced it with a paid-for service (£20 a year, although you can get some elements free, with pay-as-you-go printing), which looks like it may be quite useful. With a subscription you can print full A4 prints of 1:25,000 or 1:50,000 mapping, to set scales, and you can also add your own routes or points of interest.
Google Earth can be downloaded as a separate programme, and has very good capacity to "fly" through a landscape, showing the topography. It is possible to add routes, points and so on, and we have been experimenting with using it to display County Rare Plant Registers.
If you want to get into advanced GIS, MapInfo or ArcView are the professional versions, but cost approximately £1500 per licence, and you would need to get mapping or aerial photography data separately. Another option is QGIS, which is free, but somewhat complex - only for those wanting to be brave!
MemoryMap is a basic software package that can be used with their own data - map tiles are bought at various prices depending upon the area covered, scale and so on. It's good value for out-of-copyright OS maps, but more expensive if you wanted to cover a whole county at 1:25,000. As well as direct, you may find different deals on the OS website.
The Local Records Centres also provide some useful resources. Cofnod provides interactive mapping (you need to register but this is free) also with the vice-county boundaries for North Wales.
There is inevitably a lot of overlap between the services offered here. However, I do find that sometimes one or more are slower or faster than the others, so I do use a few different ones at times.